Don't allow read truncation or appending for file operations.

If a caller attempts to read a file with the truncation or append
bits and doesn't specify the write bit as well, silently drop the
invalid bits to prevent unintended changes.

Bug: 414387646
Test: atest CtsContentProviderTestCases
Flag: EXEMPT security fix
(cherry picked from commit f8099b06)
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:4ed6ad05b9c05cb694d8834656a4d65e61237fc0
Merged-In: I1a8993d99d1f381e1122b304d223a5c10e4578ce
Change-Id: I1a8993d99d1f381e1122b304d223a5c10e4578ce