[Android] PhotoPicker: Accessibility for remaining widgets.

The SeekBar and RemaininTime need to be marked as clickable for
TalkBack to recognize them properly.

Setting the ImportantForAccessibility flag is not enough.

Bug: 895776, 656015
Change-Id: Ifa923c460c16a88ce1bb2a479c5c623604bb55ca
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095592
Auto-Submit: Finnur Thorarinsson <finnur@chromium.org>
Commit-Queue: Theresa  <twellington@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748701}

chrome/android/java/res/layout/video_player.xml

@@ -49,7 +49,7 @@
                 android:layout_height="wrap_content"
                 android:layout_gravity="bottom|start"
                 android:layout_marginStart="16dp"
-                android:importantForAccessibility="yes"
+                android:clickable="true"
                 android:paddingBottom="24dp"
                 style="@style/TextAppearance.TextMedium.Primary.Light" />
             <ImageView
@@ -66,6 +66,7 @@
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_gravity="bottom|center"
+                android:clickable="true"
                 style="@style/PhotoPicker.SeekBar" />
         </FrameLayout>
     </FrameLayout>