Add bottom bar UI for photo page

Bug: 7050303
Bug: 7170148
Pulled the handling of the display of the edit (FX) button
out into a separate file and put in the groundwork for
supporting multiple buttons within a container along the
bottom of the screen and managing their display as well as
animating them in and out. Also added a button for launching
the panorama viewer when appropriate

Change-Id: Iee3083e0693ef3c1f55264b922f02b9a702d2103
diff --git a/res/layout/photopage_bottom_controls.xml b/res/layout/photopage_bottom_controls.xml
new file mode 100644
index 0000000..a8fca2d
--- /dev/null
+++ b/res/layout/photopage_bottom_controls.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+        android:id="@+id/photopage_bottom_controls"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_alignParentBottom="true"
+        android:layout_alignParentLeft="true"
+        android:orientation="horizontal"
+        android:visibility="gone">
+        <ImageButton
+                android:id="@+id/photopage_bottom_control_edit"
+                android:src="@drawable/photoeditor_artistic"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:visibility="gone"/>
+        <ImageButton
+                android:id="@+id/photopage_bottom_control_panorama"
+                android:src="@android:drawable/ic_dialog_map"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:visibility="gone"/>
+</LinearLayout>