Camera: ISO C++11 build fixes

Fix build in ISO C++11 mode:
- enum typesafety
- constexpr

Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
Merge remote-tracking branches 'linaro/linaro_android_4.2.2' and 'rqkang/cm-10.1' into cm-10.1