ANDROID: 16K: Fixup io_uring emulation

In the emulated __PAGE_SIZE mode, VMAs are always a multiple of
the emulated __PAGE_SIZE.

For this reason the VMA size needs to be compares with the
__PAGE_ALIGNED() size of the potentially compound page's size in
io_uring_validate_mmap_request().

Bug: 366098040
Test: atest vts_ltp_test_x86_64
Change-Id: Iac2fb439520593a1b8cd040c50d9f14ad80f4810
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>