Remove android.support.annotation.NonNull import (#1471)

Remove android.support dependency to simplify the work
with androidx.

Related issue: #1462

Author: Yuri Kulikov

android/app/src/main/java/com/microsoft/codepush/react/CodePush.java

@@ -4,7 +4,6 @@
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.res.Resources;
-import android.support.annotation.NonNull;
 
 import com.facebook.react.ReactInstanceManager;
 import com.facebook.react.ReactPackage;
@@ -82,7 +81,7 @@ public CodePush(String deploymentKey, Context context, boolean isDebugMode) {
         initializeUpdateAfterRestart();
     }
 
-    public CodePush(String deploymentKey, Context context, boolean isDebugMode, @NonNull String serverUrl) {
+    public CodePush(String deploymentKey, Context context, boolean isDebugMode, String serverUrl) {
         this(deploymentKey, context, isDebugMode);
         mServerUrl = serverUrl;
     }
@@ -93,7 +92,7 @@ public CodePush(String deploymentKey, Context context, boolean isDebugMode, int
         mPublicKey = getPublicKeyByResourceDescriptor(publicKeyResourceDescriptor);
     }
 
-    public CodePush(String deploymentKey, Context context, boolean isDebugMode, @NonNull String serverUrl, Integer publicKeyResourceDescriptor) {
+    public CodePush(String deploymentKey, Context context, boolean isDebugMode, String serverUrl, Integer publicKeyResourceDescriptor) {
         this(deploymentKey, context, isDebugMode);
 
         if (publicKeyResourceDescriptor != null) {