Support simple single select in PhotoActivity

- Add PhotosTabFragment with RecyclerView
- Add ViewHolders for RecyclerView
- Get the data from PickerViewModel
- Return the uri after the user clicks the Photo
- Grant uri read permission

Test: manual. the videos on b/169738588
Test: atest ItemTest
Bug: 169738588
Change-Id: Ie857fa4f25c82ceaca6ca2c160c109e1d15eedf2
Merged-In: Ie857fa4f25c82ceaca6ca2c160c109e1d15eedf2
(cherry picked from commit fe204ba51f297d78f35f646ac6291ec166d163a0)
diff --git a/res/values/colors.xml b/res/values/colors.xml
index ed0c6c2..96991b0 100644
--- a/res/values/colors.xml
+++ b/res/values/colors.xml
@@ -17,4 +17,9 @@
 <resources>
     <color name="thumb_gray_color">#1F000000</color>
     <color name="clear_cache_icon_color">#5F6368</color>
+
+    <!-- photo picker -->
+    <color name="picker_background_color">@android:color/white</color>
+    <color name="picker_hairline_color">#DADCE0</color>
+    <color name="picker_highlight_color">#E8F0FE</color>
 </resources>