Support ICMP tests with larger packet size

Add ping test with full MTU size and minimal IPv6 MTU size probes.
This helps to diagnose possible MTU issue in the bugreport.

Bug: 277376698
Test: adb shell dumpsys connectivity --diag
Change-Id: I0650de1f07fadcac189a40817bcc1a70be2e2b6c
1 file changed