find_input_delta: Add jar inspection, metrics generation

This change implements:
- zipfile inspection (for some file extensions)
- changed files metrics generation

Bug: b/376287012
Test: Manual, TH
Change-Id: I18a688c8c6f462cdd7526287c61d38635a9f7709
diff --git a/ui/metrics/metrics_proto/combined_metrics.proto b/ui/metrics/metrics_proto/combined_metrics.proto
new file mode 100644
index 0000000..3cd9a53
--- /dev/null
+++ b/ui/metrics/metrics_proto/combined_metrics.proto
@@ -0,0 +1,36 @@
+// Copyright 2018 Google Inc. All Rights Reserved.
+//
+// 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.
+
+syntax = "proto2";
+
+package soong_build_metrics;
+option go_package = "android/soong/ui/metrics/metrics_proto";
+
+import "cmd/find_input_delta/find_input_delta_proto/file_list.proto";
+
+// These field numbers are also found in the inner message declarations.
+// We verify that the values are the same, and that every enum value is checked
+// in combined_metrics_test.go.
+// Do not change this enum without also updating:
+//  - the submessage's .proto file
+//  - combined_metrics_test.go
+enum FieldNumbers {
+  FIELD_NUMBERS_UNSPECIFIED = 0;
+  FIELD_NUMBERS_FILE_LIST = 1;
+}
+
+message SoongCombinedMetrics {
+  // cmd/find_input_delta/find_input_delta_proto.FileList
+  optional android.find_input_delta_proto.FileList file_list = 1;
+}