AIDL effect: Add EffectProxy implementation and test

Bug: 261129656
Test: Enable AIDL in libaudiohal, Build
Test: atest EffectsProxyTest
Test: Enable AIDL and test on Pixel with YTM
Change-Id: I655d8671f64e5b237d4626be376bc9a014d5927e
diff --git a/media/libaudiohal/Android.bp b/media/libaudiohal/Android.bp
index f47dd0b..1dbcb86 100644
--- a/media/libaudiohal/Android.bp
+++ b/media/libaudiohal/Android.bp
@@ -76,3 +76,11 @@
 
     export_include_dirs: ["include"],
 }
+
+cc_library_headers {
+    name: "libaudiohalimpl_headers",
+
+    header_libs: ["libaudiohal_headers"],
+    export_header_lib_headers: ["libaudiohal_headers"],
+    export_include_dirs: ["impl"],
+}