Reset mPageSizeAppCompatFlags while upgrading

previous value of mPageSizeAppCompatFlags remains the same
when package is updagraded. Reset the value in case of the upgrade.

Test: m FileSystemUtilsTests && atest -c FileSystemUtilsTests
Test: Install 4 KB and 16 KB aligned versions of the same app.
Bug: 430567227
Flag: EXEMPT bug_fix
Change-Id: I56a70b8b75c0220a7e74b48033533487ecb83241