Fix layer removal transaction.

Layers were not properly being removed because we were
setting the wrong transaction type flag at the time of
removal.

When layers are removed, we must use eDisplayTransactionNeeded,
not eTransactionNeeded, to ensure that the mLayersRemoved
flag is checked and the appropriate cleanup occurs.

Bug: 6970310
Change-Id: Id4b2897a34d4ac00aa0f92349c0ec6db95c1aaf7