Remove getWorkspaceIconsPositions()

This cl addresses
	- removing of getWorkspaceIconsPositions()
	- addition of getWorkspaceIconPosition()

getWorkspaceIconsPositions() was not reliable as it was getting any icon selector and not actually waiting for the icon of intereset.
now we wait for specific icon of interest and tests are change accordingly.

Test: Presubmit
Bug: 319501259
Flag: TEST_ONLY

Change-Id: Ia65b9d51520763a7fbbb8d5cd3bc129496e443cc