Fix typo in ConstantsShim constant.

This change fixes a typo in the value assigned to the constant
KEY_NETWORK_PROBES_ATTEMPTED_BITMASK, which is defined in the
ConstantsShim for API level 29. This constant is a copy of the constant
of the same name defined in ConnectivityDiagnosticsManager (which is
also being updated in aosp/1226857).

Bug: 148939502
Test: compiles
Change-Id: I1f1369ad1034bcde0650bcc0f1fd69f49524a5fc