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
diff --git a/rsContext.cpp b/rsContext.cpp
index a706a8b..296c9c6 100644
--- a/rsContext.cpp
+++ b/rsContext.cpp
@@ -54,8 +54,8 @@
 }
 #endif
 
-using namespace android;
-using namespace android::renderscript;
+namespace android {
+namespace renderscript {
 
 pthread_mutex_t Context::gInitMutex = PTHREAD_MUTEX_INITIALIZER;
 pthread_mutex_t Context::gMessageMutex = PTHREAD_MUTEX_INITIALIZER;
@@ -783,9 +783,6 @@
 ///////////////////////////////////////////////////////////////////////////////////////////
 //
 
-namespace android {
-namespace renderscript {
-
 void rsi_ContextFinish(Context *rsc) {
     rsc->finish();
 }
@@ -935,5 +932,5 @@
 
 }
 
-}
-}
+} // namespace renderscript
+} // namespace android