Disable IpConnectivityMetricsTest.

This test has been failing for a while, and we are do not have
bandwidth to fix it during the next week.

Test: make -j64 FrameworksNetTests RUN_ERROR_PRONE=true
Test: atest FrameworksNetTests:IpConnectivityMetricsTest
Test: runtest -x frameworks/base/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
Change-Id: I59d73c1773e160a726996f3ab4ad20312decc127