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/rsApiAllocation.cpp b/rsApiAllocation.cpp
index 84d5692..90766e1 100644
--- a/rsApiAllocation.cpp
+++ b/rsApiAllocation.cpp
@@ -17,8 +17,8 @@
 #include "rsContext.h"
 #include "rsAllocation.h"
 
-using namespace android;
-using namespace android::renderscript;
+namespace android {
+namespace renderscript {
 
 extern "C" const void * rsaAllocationGetType(RsContext con, RsAllocation va) {
     Allocation *a = static_cast<Allocation *>(va);
@@ -26,3 +26,6 @@
 
     return a->getType();
 }
+
+} // namespace renderscript
+} // namespace android