Add the ActionBar trash and share icons.

- Adds the share drawable against dark background from ux repos.
- Removes the trash button from the main voicemail ui.
- Adds both trash and share to the ActionBar top right corner of call
  details, but only if we are looking at a voicemail.
- Adds placeholder methods for when these buttons get clicked.
- Changes other options menu elements to use the android:onClick
  property with a well-named method, rather than using switch by id.

Other changes:
- Tells proguard not to remove android:onClick style methods where those
  methods are public void and take a MenuItem or View single argument
  (exactly the type specified in xml files).
- Remove android:showAsAction property on the call detail options,
  because I don't think we want them to appear on the ActionBar at all,
  and if we did these are the wrong properties to use.
- Remove the variable storing the 'has remove from call log', we can
  just calculate that in onPrepareOptionsMenu.
- Calls through to super.onCreateOptionsMenu and
  super.onPrepareOptionsMenu rather than just returning true, as
  requested in the javadoc.

Bug: 5070929
Change-Id: I237bdcbb7b0a5135e940a0f44a64e4a39f741fa6
diff --git a/proguard.flags b/proguard.flags
index 577144b..5a08b9f 100644
--- a/proguard.flags
+++ b/proguard.flags
@@ -2,6 +2,13 @@
   public <init>(...);
 }
 
+# Xml files containing onClick (menus and layouts) require that proguard not
+# remove their handlers.
+-keepclassmembers class * extends android.app.Activity {
+  public void *(android.view.View);
+  public void *(android.view.MenuItem);
+}
+
 # TODO: Instead of keeping the following two functions we could as well just remove them completely
 # as they are only used in test code
 
@@ -16,4 +23,4 @@
 # Any methods whose name is '*ForTest' are preserved.
 -keep class ** {
   *** *ForTest(...);
-}
\ No newline at end of file
+}