Lower testing field id to 2**28 - 1

The current value of 2**29 - 1 doesn't seem to work with
Java generated code.

TBR: lalitm
Change-Id: If0359019d6e4ed67bc5fc8a6693cc0d7a20344f9
diff --git a/protos/perfetto/config/data_source_config.proto b/protos/perfetto/config/data_source_config.proto
index 1688179..2fb185a 100644
--- a/protos/perfetto/config/data_source_config.proto
+++ b/protos/perfetto/config/data_source_config.proto
@@ -75,5 +75,5 @@
 
   // This field is only used for testing.
   optional TestConfig for_testing =
-      536870911;  // 2^29 - 1, max field id for protos.
+      268435455;  // 2^28 - 1, max field id for protos supported by Java.
 }
diff --git a/protos/perfetto/config/perfetto_config.proto b/protos/perfetto/config/perfetto_config.proto
index 595011b..2ea6eae 100644
--- a/protos/perfetto/config/perfetto_config.proto
+++ b/protos/perfetto/config/perfetto_config.proto
@@ -215,7 +215,7 @@
 
   // This field is only used for testing.
   optional TestConfig for_testing =
-      536870911;  // 2^29 - 1, max field id for protos.
+      268435455;  // 2^28 - 1, max field id for protos supported by Java.
 }
 
 // End of protos/perfetto/config/data_source_config.proto
diff --git a/protos/perfetto/trace/perfetto_trace.proto b/protos/perfetto/trace/perfetto_trace.proto
index 7fb6490..19dbd0c 100644
--- a/protos/perfetto/trace/perfetto_trace.proto
+++ b/protos/perfetto/trace/perfetto_trace.proto
@@ -199,7 +199,7 @@
     bytes synchronization_marker = 36;
 
     // This field is only used for testing.
-    // removed field with id 536870911  // 2^29 - 1, max field id for protos.
+    // removed field with id 268435455  // 2^28 - 1, max field id for protos.
   }
 
   // Trusted user id of the producer which generated this packet. Keep in sync
diff --git a/protos/perfetto/trace/trace_packet.proto b/protos/perfetto/trace/trace_packet.proto
index e6fe149..51a45bb 100644
--- a/protos/perfetto/trace/trace_packet.proto
+++ b/protos/perfetto/trace/trace_packet.proto
@@ -61,7 +61,7 @@
     bytes synchronization_marker = 36;
 
     // This field is only used for testing.
-    TestEvent for_testing = 536870911;  // 2^29 - 1, max field id for protos.
+    TestEvent for_testing = 268435455;  // 2^28 - 1, max field id for protos.
   }
 
   // Trusted user id of the producer which generated this packet. Keep in sync