Fix typo in Region to avoid unexpected values

b/34193533 showed that Framework can sometimes use very large rect
(presumably to hide a window **very** far out of the screen visible
rectangle). Which results in SF freezing and using 100% of CPU.

max_value is not initialized to the right value. Really it should be
0x7FFFFFFF instead of
0x7FFFFFF
Since Region was templatized (originally to potentially use int16_t)
the fix uses C++11 numeric_limits instead of INT_MAX.

Test: Manual
Change-Id: Iaee64727226730dbea1f05618a97b801254cde4d