Revert "Make incall screen glopad background themeable"

Change I6a0a120662e4e45b5282a763c8ccf41d29c6d470 was supposed
to make only bottom half of caller photo semi-transparent. Instead
it also exposes in-call buttons at the bottom of the screen behind
the glowpad. This has looked plain broken for months.

This reverts commit 3073f8760c82198a80cf8efe3fe0e3b2804852c2.

Change-Id: I38d2b8aefdaa77385c863b97221e88f0da6a97e2
[1/2] InCall: Add a non-intrusive dialog for incoming calls

Change-Id: I7c8b5cc5138a5543be30579e99bd9989624e2abe
[3/3] InCallUI: allow disabling non intrusive incall ui

Change-Id: I86bd4b46f031004fa90f1d7936263f9dabcd3860
InCallUI: Disable Back button on Non-intursive InCall Card

Fix for jira issue http://jira.omnirom.org/browse/OMNI-296

PS2 to PS5: code cleanup

PS6: Remove Jira issue url from code

Change-Id: I257daccbb175265e2430f1b0b30c9175cb4b1981
InCallUI: fix non intrusive incallui layout

- makes the decline/answer buttons evenly sized
- decrease font size of buttons to 13sp so the non-english button labels fit better

before: https://www.dropbox.com/s/g9mn72qhzq6wlbt/2014-01-01%2006.00.31.png
after:  https://www.dropbox.com/s/dfhmaliz6a21lk5/2014-01-01%2010.30.42.png

Change-Id: I88e0f0a1358595f2ce86dddcae2ab4d4e788fc1a