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/rsSampler.cpp b/rsSampler.cpp
index 858658d..25abfb9 100644
--- a/rsSampler.cpp
+++ b/rsSampler.cpp
@@ -18,9 +18,8 @@
 #include "rsSampler.h"
 #include "rs.h"
 
-using namespace android;
-using namespace android::renderscript;
-
+namespace android {
+namespace renderscript {
 
 Sampler::Sampler(Context *rsc) : ObjectBase(rsc) {
     // Should not get called.
@@ -129,9 +128,6 @@
 
 ////////////////////////////////
 
-namespace android {
-namespace renderscript {
-
 RsSampler rsi_SamplerCreate(Context * rsc,
                             RsSamplerValue magFilter,
                             RsSamplerValue minFilter,
@@ -145,4 +141,5 @@
     return s.get();
 }
 
-}}
+} // namespace renderscript
+} // namespace android