CCodec: remove dependency to # of slots for allocating local buffers

In addition, a little build tweak for the test.

Bug: 146168540
Test: atest ccodec_unit_test:RawGraphicOutputBuffersTest
Change-Id: Ia1a0969e87ca1729bb38cf5cf1c7ec8df3029bc7
diff --git a/media/codec2/sfplugin/Codec2Buffer.h b/media/codec2/sfplugin/Codec2Buffer.h
index ff79946..dc788cd 100644
--- a/media/codec2/sfplugin/Codec2Buffer.h
+++ b/media/codec2/sfplugin/Codec2Buffer.h
@@ -20,16 +20,29 @@
 
 #include <C2Buffer.h>
 
-#include <android/hardware/cas/native/1.0/types.h>
-#include <android/hardware/drm/1.0/types.h>
 #include <binder/IMemory.h>
 #include <media/hardware/VideoAPI.h>
 #include <media/stagefright/foundation/ABuffer.h>
 #include <media/MediaCodecBuffer.h>
-#include <mediadrm/ICrypto.h>
 
 namespace android {
 
+namespace hardware {
+class HidlMemory;
+namespace cas {
+namespace native {
+namespace V1_0 {
+struct SharedBuffer;
+}  // namespace V1_0
+}  // namespace native
+}  // namespace cas
+namespace drm {
+namespace V1_0 {
+struct SharedBuffer;
+}  // namespace V1_0
+}  // namespace drm
+}  // namespace hardware
+
 /**
  * Copies a graphic view into a media image.
  *