Use {To/From}JavaTime for policy timestamps

components/policy/proto/device_management_backend.proto

Index: components/policy/proto/device_management_backend.proto
diff --git a/components/policy/proto/device_management_backend.proto b/components/policy/proto/device_management_backend.proto
index 43da70913ab018b88f858a7c6cce5556e59cb9a4..c78894fc7541ccac5c3e63eb48e535fcbace630c 100644
--- a/components/policy/proto/device_management_backend.proto
+++ b/components/policy/proto/device_management_backend.proto
@@ -286,7 +286,7 @@ message PolicyData {
   // See PolicyFetchRequest.policy_type.
   optional string policy_type = 1;
 
-  // [timestamp] is milliseconds since Epoch in UTC timezone. It is
+  // [timestamp] is milliseconds since Epoch in UTC timezone (Java time). It is

[Thiemo Nagel, 2017/04/20 14:02:13]

Nit: Could you please either re-wrap the whole paragraph at 80 characters or
stay in line with the existing (70 character) wrapping?

[emaxx, 2017/04/20 15:00:46]

Done.

   // included here so that the time at which the server issued this
   // response cannot be faked (as protection against replay attacks).
   // It is the timestamp generated by DMServer, NOT the time admin
@@ -537,7 +537,7 @@ message DevicePolicyResponse {
 }
 
 message TimePeriod {
-  // [timestamp] is milli seconds since Epoch in UTC timezone.
+  // [timestamp] is milliseconds since Epoch in UTC timezone (Java time).
   optional int64 start_timestamp = 1;
   optional int64 end_timestamp = 2;
 }