CtsVerifier: Switch camera video storage

Use the external files directory for storing camera
videos.

Bug: 134371824
Test: Manual using application
Change-Id: I8ec2e45e865732c4e308d0b0c17473dee733406f
diff --git a/apps/CtsVerifier/src/com/android/cts/verifier/camera/video/CameraVideoActivity.java b/apps/CtsVerifier/src/com/android/cts/verifier/camera/video/CameraVideoActivity.java
index 1f17cdf..c41e2ba 100644
--- a/apps/CtsVerifier/src/com/android/cts/verifier/camera/video/CameraVideoActivity.java
+++ b/apps/CtsVerifier/src/com/android/cts/verifier/camera/video/CameraVideoActivity.java
@@ -111,16 +111,12 @@
      * @see #MEDIA_TYPE_IMAGE
      * @see #MEDIA_TYPE_VIDEO
      */
-    private static File getOutputMediaFile(int type) {
-        // Question: why do I need to comment this to get it working?
-        // Logcat says "external storage not ready"
-        // if (Environment.getExternalStorageState() != Environment.MEDIA_MOUNTED) {
-        //     Log.e(TAG, "external storage not ready");
-        //     return null;
-        // }
-
-        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
-                Environment.DIRECTORY_MOVIES), TAG);
+    private File getOutputMediaFile(int type) {
+        File mediaStorageDir = new File(getExternalFilesDir(null), TAG);
+        if (mediaStorageDir == null) {
+            Log.e(TAG, "failed to retrieve external files directory");
+            return null;
+        }
 
         if (!mediaStorageDir.exists()) {
             if (!mediaStorageDir.mkdirs()) {