Audio HAL: Simplify types updates for 'common' and 'effect' packages

Instead of importing every single type individually ("using <type>"),
import entire namespaces of
::android::hardware::audio::common::CPP_VERSION and
::android::hardware::audio::effect::CPP_VERSION
inside the "implementation" namespace in the default implementation.

This simplifies modifying types, as it is not needed anymore
to surround "using <type>" directives with #if MAJOR_VERSION ...

Note that the contents of the namespaces are imported inside
the "implementation" namespace, which reduces risks of name collision

Test: make
Change-Id: I5daa0ed91203726d1df67408ac9af728c247704a
diff --git a/audio/effect/all-versions/default/LoudnessEnhancerEffect.h b/audio/effect/all-versions/default/LoudnessEnhancerEffect.h
index 6eb8a8c..06c521c 100644
--- a/audio/effect/all-versions/default/LoudnessEnhancerEffect.h
+++ b/audio/effect/all-versions/default/LoudnessEnhancerEffect.h
@@ -39,18 +39,8 @@
 using ::android::hardware::hidl_vec;
 using ::android::hardware::Return;
 using ::android::hardware::Void;
-using ::android::hardware::audio::common::CPP_VERSION::AudioDevice;
-using ::android::hardware::audio::common::CPP_VERSION::AudioMode;
-using ::android::hardware::audio::common::CPP_VERSION::AudioSource;
-using ::android::hardware::audio::effect::CPP_VERSION::AudioBuffer;
-using ::android::hardware::audio::effect::CPP_VERSION::EffectAuxChannelsConfig;
-using ::android::hardware::audio::effect::CPP_VERSION::EffectConfig;
-using ::android::hardware::audio::effect::CPP_VERSION::EffectDescriptor;
-using ::android::hardware::audio::effect::CPP_VERSION::EffectOffloadParameter;
-using ::android::hardware::audio::effect::CPP_VERSION::IEffect;
-using ::android::hardware::audio::effect::CPP_VERSION::IEffectBufferProviderCallback;
-using ::android::hardware::audio::effect::CPP_VERSION::ILoudnessEnhancerEffect;
-using ::android::hardware::audio::effect::CPP_VERSION::Result;
+using namespace ::android::hardware::audio::common::CPP_VERSION;
+using namespace ::android::hardware::audio::effect::CPP_VERSION;
 
 struct LoudnessEnhancerEffect : public ILoudnessEnhancerEffect {
     explicit LoudnessEnhancerEffect(effect_handle_t handle);