Remove unnecessary request for External Storage

Since we use app internal storage and then a contentProvider, I don't think we need permission for external storage. It's up to the external content provider (e.g. files, drive etc) to have access to the appropriate storage.

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

@@ -6,7 +6,6 @@
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
-    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
 
     <uses-feature android:name="android.hardware.camera" android:required="false" />
     <uses-feature android:name="android.hardware.microphone" android:required="false" />

android/ScratchJr/app/src/main/java/org/scratchjr/android/ScratchJrActivity.java

@@ -183,11 +183,9 @@ public void run() {
     public void requestPermissions() {
         cameraPermissionResult = ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA);
         micPermissionResult = ContextCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO);
-        readExtPermissionResult = ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE);
 
         if (cameraPermissionResult == PackageManager.PERMISSION_GRANTED
-            && micPermissionResult == PackageManager.PERMISSION_GRANTED
-            && readExtPermissionResult == PackageManager.PERMISSION_GRANTED) {
+            && micPermissionResult == PackageManager.PERMISSION_GRANTED) {
             return;
         }
 
@@ -198,9 +196,6 @@ public void requestPermissions() {
         if (micPermissionResult != PackageManager.PERMISSION_GRANTED) {
             tmp.add(Manifest.permission.RECORD_AUDIO);
         }
-        if (readExtPermissionResult != PackageManager.PERMISSION_GRANTED) {
-            tmp.add(Manifest.permission.READ_EXTERNAL_STORAGE);
-        }
         Object[] tmpArray = tmp.toArray();
         String[] desiredPermissions = Arrays.copyOf(tmpArray, tmpArray.length, String[].class);
 
@@ -221,9 +216,6 @@ public void onRequestPermissionsResult(int requestCode,
                 if (permission.equals(Manifest.permission.RECORD_AUDIO)) {
                     micPermissionResult = grantResults[permissionId];
                 }
-                if (permission.equals(Manifest.permission.READ_EXTERNAL_STORAGE)) {
-                    readExtPermissionResult = grantResults[permissionId];
-                }
                 permissionId++;
             }
         }