Move AudioGain to libaudiofoundation.

1. Create folder for libaudiofoudation.
2. Move AudioGain to libaudiofoudation. The goal is to make AudioGain
be able to use in binder call and be vendor-available later.

Bug: 135621476
Test: make, CTS for AudioTrack, AudioRecord, AudioManagerTest
Change-Id: Ibf16ad9cb7f2ac657a02632ccbe4f934b5a12731
diff --git a/media/libaudiofoundation/Android.bp b/media/libaudiofoundation/Android.bp
new file mode 100644
index 0000000..5045d87
--- /dev/null
+++ b/media/libaudiofoundation/Android.bp
@@ -0,0 +1,33 @@
+cc_library_headers {
+    name: "libaudiofoundation_headers",
+    vendor_available: true,
+    export_include_dirs: ["include"],
+}
+
+cc_library_shared {
+    name: "libaudiofoundation",
+    vendor_available: true,
+
+    srcs: [
+        "AudioGain.cpp",
+    ],
+
+    shared_libs: [
+        "libbase",
+        "libbinder",
+        "liblog",
+        "libutils",
+    ],
+
+    header_libs: [
+        "libaudio_system_headers",
+        "libaudiofoundation_headers",
+    ],
+
+    export_header_lib_headers: ["libaudiofoundation_headers"],
+
+    cflags: [
+        "-Werror",
+        "-Wall",
+    ],
+}