Fix google-build-using-namespace warnings in rs. * Most files define classes in renderscript namespace. Define them in the namespace instead of "using namespace ...". Some files define global C++ names, and we replace "using namespace ..." with using declarations of the required names. * Add "NOLINT" comment to rsg_generator.c output code to suppress such warnings. Bug: 32670901 Test: build with WITH_TIDY=1 Change-Id: I9b0edcad3e1fb37c79927b05fd58fb1a301bdf22