Fix grammar for AggregateMultiTenancyIsolation

This section started with a sentence fragment
Fix fragment and combine the last two sentences for clarity

Change-Id: I4730976396359e416ac9bf06f32901d37870ebdf
Closes-Bug: #1344276
Co-Authored-By: Nathaniel Dillon
Merge "Fix grammar for AggregateMultiTenancyIsolation"