Fix google-build-using-namespace warnings in driver.

* Replace "using namespace ..." statements with
  using declarations of the required names.
* Put extern "C" functions inside a namespace to save
  a lot of using declarations. Their linkage names are not
  changed but can access names in the namespace easily.

Bug: 32670901
Test: build with WITH_TIDY=1
Change-Id: I7a2d45ecab47bc9064701fd288fe31f47b28fcc9
diff --git a/driver/rsdBcc.cpp b/driver/rsdBcc.cpp
index 5aa1c94..4c1f521 100644
--- a/driver/rsdBcc.cpp
+++ b/driver/rsdBcc.cpp
@@ -31,9 +31,14 @@
 #include "utils/StopWatch.h"
 #endif
 
-using namespace android;
-using namespace android::renderscript;
-
+using android::renderscript::Allocation;
+using android::renderscript::Context;
+using android::renderscript::Element;
+using android::renderscript::ObjectBase;
+using android::renderscript::RsdCpuReference;
+using android::renderscript::Script;
+using android::renderscript::ScriptC;
+using android::renderscript::rs_script;
 
 bool rsdScriptInit(const Context *rsc,
                      ScriptC *script,