Fix PrivateAddressCoordinatorTest#testReservedPrefix

The intention of this test case is to check that the cached hotspot prefix doesn't get assigned to ethernet, even if released, so that it can be offered to the hotspot if requested again.

Therefore we should call `requestStickyDownstreamAddress` instead of `requestDownstreamAddress` when requesting the prefix for hotspot.

Bug: 375858174

Test: atest TetheringTests:com.android.networkstack.tethering.PrivateAddressCoordinatorTest#testReservedPrefix --iteration 200

Change-Id: I5d897aa958a9549f3d773bd59920906a815edb5e

1 file changed