Create a header-only library for atrace in platform NDK builds

App NDK has access to libandroid for tracing APIs in trace.h. These APIs
wrap libcutils atrace methods.
Vendor does not have access to libandroid, but does have access to
libcutils.
To keep the code portable, libandroid_trace is created for the
platform NDK. Now both variants can include android/trace.h, use the
same APIs, and just link with the different libraries(libandroid for
apps, libandroid_trace and libcutils for platform code).

Test: Build and run aidl interfaces(-ndk and -ndk_platform) with these tracing calls.
Bug: 128533039
Change-Id: Iba5917a06fd58573265dcaf5658c4958d8f591dc

native/android/Android.bp

@@ -93,6 +93,14 @@ cc_library_shared {
     },
 }
 
+// Header-only library used for atrace in platform NDK builds
+cc_library_headers {
+    name: "libandroid_trace",
+    host_supported: true,
+    vendor_available: true,
+    export_include_dirs: ["trace"],
+}
+
 // Network library.
 cc_library_shared {
     name: "libandroid_net",
@@ -137,4 +145,4 @@ filegroup {
         "aidl/com/android/internal/compat/IPlatformCompatNative.aidl",
     ],
     path: "aidl",
-}
\ No newline at end of file
+}

native/android/trace/android/trace.h

+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef ANDROID_ATRACE_HEADERS_H
+#define ANDROID_ATRACE_HEADERS_H
+
+#include <cutils/trace.h>
+
+inline void ATrace_beginSection(const char* sectionName) {
+    atrace_begin(ATRACE_TAG_APP, sectionName);
+}
+
+inline void ATrace_endSection() {
+    atrace_end(ATRACE_TAG_APP);
+}
+
+#endif // ANDROID_ATRACE_HEADERS_H