Convert IEffect and IEffectClient to AIDL

This change replaces the manually-parceled IEffect and IEffectClient
with AIDL definitions.

In addition, this includes a small library that facilitates shared
memory regions over AIDL.

Bug: 160253486
Test: Ran effects-related CTS tests. Manual verification of basic
      audio functionality on Sargo.

Change-Id: I5a9c5f2f24c10072ad5067acc71aa30581af41c1
diff --git a/services/audioflinger/DeviceEffectManager.h b/services/audioflinger/DeviceEffectManager.h
index c6d2110..d187df2 100644
--- a/services/audioflinger/DeviceEffectManager.h
+++ b/services/audioflinger/DeviceEffectManager.h
@@ -33,7 +33,7 @@
     sp<EffectHandle> createEffect_l(effect_descriptor_t *descriptor,
                 const AudioDeviceTypeAddr& device,
                 const sp<AudioFlinger::Client>& client,
-                const sp<IEffectClient>& effectClient,
+                const sp<media::IEffectClient>& effectClient,
                 const std::map<audio_patch_handle_t, PatchPanel::Patch>& patches,
                 int *enabled,
                 status_t *status,