Add play icon to the gesture settings videos.

1. Add a play button icon to show on top of the gesture videos when the
video is not playing.
2. Dynamically split the gesture video and description text in half
instead of using the hard coded value.
3. Hide the video view if animation is not available.
4. Delay removing the animation preview till the video starts drawing on
the surface texture.

Bug: 28565958
Change-Id: I8b954828d16286014404172d29efa4d2e00432b3
diff --git a/res/values/dimens.xml b/res/values/dimens.xml
index c4e471f..9a97d30 100755
--- a/res/values/dimens.xml
+++ b/res/values/dimens.xml
@@ -297,10 +297,6 @@
     <dimen name="redaction_padding_start">16dp</dimen>
 
     <!-- Padding for Gestures settings screen -->
-    <dimen name="gestures_settings_title_height">56dp</dimen>
-    <dimen name="gestures_settings_video_height">206dp</dimen>
-    <dimen name="gestures_settings_video_width">206dp</dimen>
-    <dimen name="gestures_settings_summary_height">206dp</dimen>
-    <dimen name="gestures_settings_summary_width">206dp</dimen>
     <dimen name="gestures_settings_padding_top_bottom">20dp</dimen>
+    <dimen name="gestures_play_button_size">36dp</dimen>
 </resources>