Jarjar com.google.protobuf

This avoids potential conflicts if the library is also added to the
bootclasspath.

com.google.protobuf is pulled as a dependency when adding protobuffers,
like those used for data stall, IP provisioning and validation metrics.

Bug: 159587267
Test: m; manual: booted, wifi working

Change-Id: I3339e47c1ca1cd8b0186da0dbf880eff245b4c67
diff --git a/Android.bp b/Android.bp
index 6ccbd18..ae19a1c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -91,6 +91,7 @@
         "netlink-client",
         "networkstack-client",
         "net-utils-framework-common",
+        // See note on statsprotos when adding/updating proto build rules
         "datastallprotosnano",
         "statsprotos",
         "captiveportal-lib",
@@ -293,6 +294,8 @@
     required: ["NetworkPermissionConfig"],
 }
 
+// When adding or modifying protos, the jarjar rules and possibly proguard rules need
+// to be updated: proto libraries may pull additional static libraries.
 java_library_static {
     name: "statsprotos",
     proto: {