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

Instead of importing every single type individually ("using <type>"),
import entire namespaces of
::android::hardware::audio::CPP_VERSION and
::android::hardware::audio::common::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

Also, fixed the namespace for HidlUtils--it needs to be in
'implementation'.

Test: make
Change-Id: I81bbb3074b5763717ae72e747a075fd46dc36d18
diff --git a/audio/effect/all-versions/default/EffectsFactory.cpp b/audio/effect/all-versions/default/EffectsFactory.cpp
index d2d8a46..6283e7b 100644
--- a/audio/effect/all-versions/default/EffectsFactory.cpp
+++ b/audio/effect/all-versions/default/EffectsFactory.cpp
@@ -32,8 +32,6 @@
 #include "VisualizerEffect.h"
 #include "common/all-versions/default/EffectMap.h"
 
-using ::android::hardware::audio::common::CPP_VERSION::HidlUtils;
-
 #include <android/log.h>
 #include <media/EffectsFactoryApi.h>
 #include <system/audio_effects/effect_aec.h>
@@ -48,8 +46,6 @@
 #include <system/audio_effects/effect_virtualizer.h>
 #include <system/audio_effects/effect_visualizer.h>
 
-using ::android::hardware::audio::common::CPP_VERSION::HidlUtils;
-
 namespace android {
 namespace hardware {
 namespace audio {
@@ -57,6 +53,8 @@
 namespace CPP_VERSION {
 namespace implementation {
 
+using ::android::hardware::audio::common::CPP_VERSION::implementation::HidlUtils;
+
 // static
 sp<IEffect> EffectsFactory::dispatchEffectInstanceCreation(const effect_descriptor_t& halDescriptor,
                                                            effect_handle_t handle) {