Followup dd1c7f7fd7: fix LESSification errors in Parsoid styles

.mw-halign-right should probably have float: right;, not float: left;

Also, use & because .mw-halign-* are applied to <figure>, not its descendants.

Bug: 65596
Change-Id: I7cd00f0049523f064703d7355b80457a4ab5d0d0