Test to verify that grid item's stretched size is reset when changing to a different alignment value.

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PASS Checking stretched size before changing to self-start. 
PASS Checking size after changing to self-start. 
PASS Checking stretched size before changing to self-end. 
PASS Checking size after changing to self-end. 
PASS Checking stretched size before changing to start. 
PASS Checking size after changing to start. 
PASS Checking stretched size before changing to end. 
PASS Checking size after changing to end. 
PASS Checking stretched size before changing to center. 
PASS Checking size after changing to center. 
PASS Checking stretched size before changing to baseline. 
PASS Checking size after changing to baseline.