fix(core): remove dev menu app icon

Issue #, if available: 794

Description of changes: Removes the intent filter from the developer menu activity in the AndroidManifest to avoid creating a second app icon for the developer menu when running the app.

Author: eeatonaws

core/src/main/AndroidManifest.xml

@@ -19,12 +19,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
     <application>
         <activity android:name="com.amplifyframework.devmenu.DeveloperMenuActivity"
-            android:theme="@style/OverlayActivity">
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
-        </activity>
+            android:theme="@style/OverlayActivity" />
     </application>
 </manifest>