improve resize transactions

use a flag instead of pre-committing the "requested" state
to prevent propagation or "requested" to "active", which makes
things a lot clearer when reading the code.

also avoid going through the "resized" code-path when requested
size is equal to "active" size.

Bug: 6498869
Change-Id: I24f893ba0ec5ca06aac5b8da9818989ae7ce4005