Increased the number of rows of AbuseFilter's Examine Past diffs table

The text areas for the table row had only 5 rows initially which was
small and it needed scroll to view it completely.
Now it has been changed to 25.

Bug: 59866
Change-Id: I77a092ac956bd9a9e4b7eb38abb16876087b8560
Merge "Increased the number of rows of AbuseFilter's Examine Past diffs table"