Revert part of eb49009d02 (#5230)

This reverts the removal of Droid Sans as fallback font. The
license for this font used to be GPL2. I've updated the font
files to Liberation 2.00, which are SIL, and do not require
us to ship source code.

I've attempted to fix all the attribution and license strings,
and used the strings as provided by redhat for attribution
to make sure they're correct.

Last, I've removed a bunch of executable bits on files that do
not need them.

Fixes #5231

fonts/DroidSansFallbackFull-LICENSE.txt

@@ -0,0 +1,13 @@
+Copyright (C) 2008 The Android Open Source Project
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.