Importer: Full-screen viewing, UI refinement, refactoring

Bug: 7990333
Bug: 8151814
Bug: 8037411

This CL adds or changes the following things:
 - Full-screen image viewing and UI for switching modes
 - Moved general functionality from MtpThumbnailTileView
   to MtpImageView to allow for reuse in full-screen image
   use-case
 - MtpBitmapCache moved from ui to data package
 - Orientation now respected when set in image metadata
 - Miscellaneous UI consistency issues fixed
 - Miscellaneous instability issues fixed

Change-Id: I5f188b763617b693e32fedc03273d711d604922a
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 4cb3089..78a6db1 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -179,6 +179,7 @@
          media from attached MTP devices, like cameras and camera phones -->
         <activity android:launchMode="singleInstance"
             android:taskAffinity="" android:name="com.android.gallery3d.ingest.IngestActivity"
+            android:configChanges="orientation|screenSize"
             android:label="@string/app_name">
             <intent-filter>
                 <action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />