Clean up SubMgr#getOpportunisticSubscriptions.

Remove param slotIndex, which is not used.

Bug: 117832560
Bug: 117830188
Test: build
Change-Id: Iac892044d336542b103eca2908420d8fd16e59c8
Merged-In: Iac892044d336542b103eca2908420d8fd16e59c8
2 files changed