Fix google-build-using-namespace warnings.

Replace "using namespace ..." with "using namespace::identifier"
for every imported identifiers.

Bug: 32670901
Test: make with WITH_TIDY=1
Change-Id: Iae11a95b386c7e783e3bc50312a8fd4209e4ced7

cpp/Sampler.cpp

diff --git a/cpp/Sampler.cpp b/cpp/Sampler.cpp
index 5aebd86..1079e1c 100644
--- a/cpp/Sampler.cpp
+++ b/cpp/Sampler.cpp
@@ -17,8 +17,8 @@
 #include "RenderScript.h"
 #include "rsCppInternal.h"
 
-using namespace android;
-using namespace RSC;
+using android::RSC::Sampler;
+using android::RSC::sp;
 
 Sampler::Sampler(sp<RS> rs, void* id):
     BaseObj(id, rs)