Specify source file encoding as UTF-8

This setting specifies how build plugins and IDEs should treat files
in the project. If it is not specified, then the editor default for
file creation and editing, and the build system default for analyzing
content, defaults to the default encoding of the current system. The
setting is necessary to ensure that the project behaves the same way
across all operating systems and locales.

Change-Id: I5a0b78dce03b7503451064bda7453a7def156e88
Merge "Specify source file encoding as UTF-8"