startTrackDefaultNetwork was allowed to called multiple times
before even though there is no one actually do it. However,
in the TetheringTest#verifyDefaultNetworkRequestFiled, a
manual invocation is used to ensure that function supports
multiple entrance.
But with aosp/1697371, startTrackDefaultNetwork is no longer
allowed to be called multiple times, it would lead to log.wtf
and crash system in eng build.
Since the manual invocation of startTrackDefaultNetwork is not
realistic and no longer valid anymore, remove the invocation
that caused the trouble.
Test: atest TetheringCoverageTests
Bug: 188613493
Merged-In: I61f6088783d521fd17ae1e87370842b4239fbe75
Change-Id: I61f6088783d521fd17ae1e87370842b4239fbe75
(cherry-picked from aosp/1711433)
9c5d40beca