Add share voicemail functionality.

+Send intent to other applications with temporary file permission
granted
+Add voicemails folder to FileProvider paths
+When creating file in VoicemailArchiveProvider, append extension to
file name
+Check voicemail content exists before archiving it
+Refactor voicemail code
+Add tests for checking file extension
+Add tests for archiving and sharing vociemails
+Archive tab should not archive on share button press

BUG=22798485

Change-Id: Id8068aba92f7f1ca58532dca6c405cb2908841a3
diff --git a/res/xml/file_paths.xml b/res/xml/file_paths.xml
index 45caed2..365a603 100644
--- a/res/xml/file_paths.xml
+++ b/res/xml/file_paths.xml
@@ -16,5 +16,7 @@
 
 <paths xmlns:android="http://schemas.android.com/apk/res/android">
     <!-- Offer access to files under Context.getCacheDir() -->
-    <cache-path name="my_cache" />
+     <cache-path name="my_cache" />
+     <!-- Offer access to voicemail folder under Context.getFilesDir() -->
+     <files-path name="voicemails" path="voicemails/" />
 </paths>