frameworks/av: Fix build in ISO C++ 11 mode

Fix build in ISO C++ 11 mode: constructs that are being interpreted as
new string literals and const vs. constexpr

Change-Id: Ibdf4867da37b819b1a499180edcf7ad480b6b9de
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
av: More ISO C++ 11 fixes

Change-Id: I84bfab66d561cb0ded6e312b8cfe02e5fe2a182f
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
av: Fix build in ISO C++11 mode

Change-Id: I461d8ce5b24afedee245a6441b600df286c76b63
Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>