Unit test for intent spam

Add unit test to test feature
BROADCAST_NETWORK_STATS_UPDATED_RATE_LIMIT_ENABLED_FLAG.
When feature is on, broadcast message should be delivered
with the designated interval(b/343844995),
When feature is off, each message should be delivered
regardless of previous intent.

Test: atest FrameworksNetTests:android.net.connectivity.com.android\
	.server.net.NetworkStatsServiceTest\
	#testNetworkStatsUpdatedIntentSpam_rateLimitOn
Test: atest FrameworksNetTests:android.net.connectivity.com.android\
	.server.net.NetworkStatsServiceTest\
	#testNetworkStatsUpdatedIntentSpam_rateLimitOff
Bug: 343844995
Change-Id: I4b89497c336a310c6959db579ca9ae3c572ff70c
2 files changed