fakehwc, libvr_hwc-hal: ComposerClient is moved

ComposerClient is moved to another library with some changes.  This
allows us to kill the has-a relation between VrComposerClient and
ComposerClientImpl in VR.

Test: builds
Change-Id: I0c32386f7d62f33e2e4d1271be42953f6880fd75
diff --git a/services/surfaceflinger/tests/fakehwc/FakeComposerService.h b/services/surfaceflinger/tests/fakehwc/FakeComposerService.h
index 5204084..c439b7e 100644
--- a/services/surfaceflinger/tests/fakehwc/FakeComposerService.h
+++ b/services/surfaceflinger/tests/fakehwc/FakeComposerService.h
@@ -16,10 +16,10 @@
 
 #pragma once
 
-#include "ComposerClient.h"
+#include <composer-hal/2.1/ComposerClient.h>
 
 using namespace android::hardware::graphics::composer::V2_1;
-using namespace android::hardware::graphics::composer::V2_1::implementation;
+using namespace android::hardware::graphics::composer::V2_1::hal;
 using android::hardware::Return;
 
 namespace sftest {