android: Add build targets librxcpp and librxcpp-tests

RxCpp tests are written with Catch2 test framework (external/catch2)
and with this and the previous commit all tests are passing.

Test: make librxcpp-tests # and then run the tests on host
Change-Id: If5598b7d9112f046ea40ead88827316c3dc44c9a
diff --git a/Android.bp b/Android.bp
new file mode 100644
index 0000000..bb5a423
--- /dev/null
+++ b/Android.bp
@@ -0,0 +1,34 @@
+// Copyright (C) 2018 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.
+
+cc_library_headers {
+  name: "librxcpp",
+  host_supported: true,
+  export_include_dirs: ["Rx/v2/src"]
+}
+
+cc_test {
+  name: "librxcpp-tests",
+  host_supported: true,
+  srcs: [
+    "Rx/v2/test/**/*.cpp",
+  ],
+  whole_static_libs: ["libcatch2-upstream"],
+  header_libs: ["librxcpp"],
+  gtest: false,
+  // Temporarily allow exceptions for all the use of try/catch in rxcpp.
+  cflags: ["-fexceptions"],
+  // Enable RTTI required to compile libcatch.
+  rtti: true,
+}