Add C++ Unit Tests for Android (#2563)

test/android/app/src/main/AndroidManifest.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-          package="com.mapbox.mapboxsdk.maps.test_runner"
           android:versionCode="1"
           android:versionName="1.0">
   <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
@@ -15,6 +14,7 @@
       android:hasCode="true">
 
     <activity android:name="android.app.NativeActivity"
+              android:exported="true"
               android:label="@string/app_name"
               android:configChanges="orientation|keyboardHidden"
               android:screenOrientation="portrait">