Allow VFS2 gofer client to mmap from sentry page cache when forced.
Allow VFS2 gofer client to mmap from sentry page cache when forced.

PiperOrigin-RevId: 381982257

google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor,google/gvisor