health AIDL: add vts tests

This is a direct translation of the health 2.0
and 2.1 VTS tests.

Some slight modifications are made (e.g. use googlemock
matchers) to make the test code more readable.

Test: run on Pixel
Bug: 203245778

Change-Id: Ifc3799a04a6a09d0d53f400b60d19fbfe004a3e3
diff --git a/health/utils/libhealthtest/Android.bp b/health/utils/libhealthtest/Android.bp
new file mode 100644
index 0000000..dbe02d6
--- /dev/null
+++ b/health/utils/libhealthtest/Android.bp
@@ -0,0 +1,29 @@
+// Copyright (C) 2021 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.
+
+// Utils library for VTS tests.
+cc_library_headers {
+    name: "libhealthtest_headers",
+    static_libs: [
+        "libgmock",
+        "libgtest",
+    ],
+    export_static_lib_headers: [
+        "libgmock",
+        "libgtest",
+    ],
+    export_include_dirs: [
+        "include",
+    ],
+}