Ensure IterableTrampolineActivity always launched (#553) (#618)

- Ensure IterableTrampolineActivity always launched to handle all notifications
- Reverts back to launchMode="singleInstance" to ensure that the activity is always launched
- Use excludeFromRecents="true" to ensure that the activity is not shown in the recent apps list

Co-authored-by: Tim Nortman <[email protected]>

Author: Ayyanchira

iterableapi/src/main/AndroidManifest.xml

@@ -25,7 +25,8 @@
         <activity
             android:name=".IterableTrampolineActivity"
             android:exported="false"
-            android:launchMode="singleTop"
+            android:launchMode="singleInstance"
+            android:excludeFromRecents="true"
             android:theme="@style/TrampolineActivity.Transparent"/>
     </application>