Add licenses for open source libraries.

Bug: 19619800
Change-Id: I4b6db840ece67c027e40cf5b5d8b4634a710950b
(cherry picked from commit 1fbd92fe04a5a37905dc0764ce062b227df5f520)

mobile/libs/licenses/CastCompanionLibrary-debug.aar.LICENSE

@@ -0,0 +1,14 @@
+Copyright 2014 Google Inc.
+
+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.
+

mobile/libs/licenses/gradle.LICENSE

@@ -0,0 +1,14 @@
+Copyright 2007-2011 the original author or authors
+
+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.
+