Add "option javanano_use_deprecated_package = true;\n" to protos compiled with the nano proto compiler that are referenced in Java files.

Bug: 21273801
Change-Id: I6d9986f5f93980d8a3400e488609a28082fc2cdb
diff --git a/protos/backup.proto b/protos/backup.proto
index 44c4b09..42873b5 100644
--- a/protos/backup.proto
+++ b/protos/backup.proto
@@ -18,6 +18,7 @@
 
 package launcher_backup;
 
+option javanano_use_deprecated_package = true;
 option java_package = "com.android.launcher3.backup";
 option java_outer_classname = "BackupProtos";