add "was_used_before" pixel param for Duck.ai launches originating on the Input Screen (#6739)

Task/Issue URL:
https://app.asana.com/1/137249556945/project/1208671518894266/task/1211247695189653?focus=true

### Description
Adds "was_used_before" pixel param for Duck.ai launches originating on
the Input Screen.

### Steps to test this PR
- [x] Clean install the app.
- [x] Go to Settings -> AI Features.
- [x] Enable the experimental address bar.
- [x] Go to browser and click on the omnibar.
- [x] Switch to Duck.ai and submit a prompt.
- [x] Verify that `m_aichat_experimental_omnibar_prompt_submitted_count`
is sent with `was_used_before=0` param.
- [x] Go to browser again and click on the omnibar.
- [x] Switch to Duck.ai and submit a prompt.
- [x] Verify that `m_aichat_experimental_omnibar_prompt_submitted_count`
is sent with `was_used_before=1` param.

Author: LukasPaczos

duckchat/duckchat-impl/src/main/java/com/duckduckgo/duckchat/impl/inputscreen/ui/viewmodel/InputScreenViewModel.kt

@@ -375,18 +375,22 @@ class InputScreenViewModel @AssistedInject constructor(
     }
 
     fun onChatSubmitted(query: String) {
-        if (isWebUrl(query)) {
-            command.value = Command.SubmitSearch(query)
-        } else {
-            command.value = Command.SubmitChat(query)
-            duckChat.openDuckChatWithAutoPrompt(query)
-        }
-        pixel.fire(DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED)
-        pixel.fire(DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED_DAILY, type = Daily())
-        inputScreenDiscoveryFunnel.onPromptSubmitted()
-        inputScreenSessionUsageMetric.onPromptSubmitted()
-
         viewModelScope.launch {
+            val wasDuckAiOpenedBefore = duckChat.wasOpenedBefore()
+            if (isWebUrl(query)) {
+                command.value = Command.SubmitSearch(query)
+            } else {
+                command.value = Command.SubmitChat(query)
+                duckChat.openDuckChatWithAutoPrompt(query)
+            }
+
+            val params = mapOf(DuckChatPixelParameters.WAS_USED_BEFORE to wasDuckAiOpenedBefore.toBinaryString())
+            pixel.fire(pixel = DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED, parameters = params)
+            pixel.fire(DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED_DAILY, type = Daily())
+
+            inputScreenDiscoveryFunnel.onPromptSubmitted()
+            inputScreenSessionUsageMetric.onPromptSubmitted()
+
             sessionStore.setHasUsedChatMode(true)
             checkAndFireBothModesPixel()
         }

duckchat/duckchat-impl/src/test/kotlin/com/duckduckgo/duckchat/impl/ui/inputscreen/InputScreenViewModelTest.kt

@@ -68,11 +68,12 @@ class InputScreenViewModelTest {
     private val inputScreenSessionUsageMetric: InputScreenSessionUsageMetric = mock()
 
     @Before
-    fun setup() {
+    fun setup() = runTest {
         whenever(autoCompleteSettings.autoCompleteSuggestionsEnabled).thenReturn(true)
         whenever(autoComplete.autoComplete(any())).thenReturn(
             flowOf(AutoCompleteResult("", listOf(AutoCompleteDefaultSuggestion("suggestion")))),
         )
+        whenever(duckChat.wasOpenedBefore()).thenReturn(false)
     }
 
     private fun createViewModel(currentOmnibarText: String = ""): InputScreenViewModel {
@@ -852,14 +853,35 @@ class InputScreenViewModelTest {
 
     @Test
     fun `when onChatSubmitted then prompt submitted pixels are fired`() = runTest {
+        whenever(duckChat.wasOpenedBefore()).thenReturn(false)
         val viewModel = createViewModel()
 
         whenever(inputScreenSessionStore.hasUsedSearchMode()).thenReturn(false)
         whenever(inputScreenSessionStore.hasUsedChatMode()).thenReturn(false)
 
         viewModel.onChatSubmitted("prompt")
 
-        verify(pixel).fire(DuckChatPixelName.DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED)
+        verify(pixel).fire(
+            pixel = DuckChatPixelName.DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED,
+            parameters = mapOf(DuckChatPixelParameters.WAS_USED_BEFORE to "0"),
+        )
+        verify(pixel).fire(DuckChatPixelName.DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED_DAILY, type = Daily())
+    }
+
+    @Test
+    fun `when onChatSubmitted and DuckChat was used before then prompt submitted pixel includes was_used_before parameter as 1`() = runTest {
+        whenever(duckChat.wasOpenedBefore()).thenReturn(true)
+        val viewModel = createViewModel()
+
+        whenever(inputScreenSessionStore.hasUsedSearchMode()).thenReturn(false)
+        whenever(inputScreenSessionStore.hasUsedChatMode()).thenReturn(false)
+
+        viewModel.onChatSubmitted("prompt")
+
+        verify(pixel).fire(
+            pixel = DuckChatPixelName.DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED,
+            parameters = mapOf(DuckChatPixelParameters.WAS_USED_BEFORE to "1"),
+        )
         verify(pixel).fire(DuckChatPixelName.DUCK_CHAT_EXPERIMENTAL_OMNIBAR_PROMPT_SUBMITTED_DAILY, type = Daily())
     }