Make DataStallReport Parcelable.

DataStallReport is defined inside ConnectivityDiagnosticsManager. In
order for DataStallReport to be used in aidls, it must implement the
Parcelable interface.

Bug: 143187964
Test: compiles
Test: atest FrameworksNetTests
Change-Id: Idbb4885e2f67fb3f85d406a622ae45d34492dca4
diff --git a/core/java/android/net/ConnectivityDiagnosticsManager.aidl b/core/java/android/net/ConnectivityDiagnosticsManager.aidl
index e31519a..82ba0ca 100644
--- a/core/java/android/net/ConnectivityDiagnosticsManager.aidl
+++ b/core/java/android/net/ConnectivityDiagnosticsManager.aidl
@@ -17,4 +17,5 @@
 
 package android.net;
 
-parcelable ConnectivityDiagnosticsManager.ConnectivityReport;
\ No newline at end of file
+parcelable ConnectivityDiagnosticsManager.ConnectivityReport;
+parcelable ConnectivityDiagnosticsManager.DataStallReport;
\ No newline at end of file