Correct rounding in PipSizeSpecHandler

Make sure to use rounding instead of flooring
while calculating maxWidth in PipSizeSpecHandler

Bug: 285638992
Test: atest WMShellUnitTests:PipSizeSpecHandlerTest
Test: atest PinnedStackTests

Change-Id: I648f6e4700e246c200952d6ae509aa70117c6dc9
2 files changed