Refactor existing android tz generation tools

Refactor existing android tz generation tools to enable the addition of
other, similar tools.

Also, switch to atest for the test code.

This commit contains small corrects to comments and a test fix.

Bug: 143451294
Test: atest tztools_common_tests
Test: atest tzlookup_generator_test
Change-Id: Ib1ca79afd711a8c7b133c8e85aba6ca6818905e5
diff --git a/input_tools/android/common/Android.bp b/input_tools/android/common/Android.bp
new file mode 100644
index 0000000..4baf656
--- /dev/null
+++ b/input_tools/android/common/Android.bp
@@ -0,0 +1,43 @@
+// Copyright (C) 2019 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.
+
+
+// Code common to various time zone host tools.
+java_library_host {
+    name: "tztools_common",
+
+    srcs: ["src/main/java/**/*.java"],
+}
+
+// Code common to various time zone host tests.
+java_library_host {
+    name: "tztools_common_testing",
+
+    srcs: ["src/testing/java/**/*.java"],
+    libs: [
+        "junit",
+    ],
+}
+
+// Tests for tztools_common and tztools_common_testing.
+java_test_host {
+    name: "tztools_common_tests",
+
+    srcs: ["src/test/java/**/*.java"],
+    static_libs: [
+        "junit",
+        "tztools_common",
+        "tztools_common_testing",
+    ],
+}