ANDROID: ABI: modify exports for find_vma

A previous change [1] inlined find_vma function, resulting in its
removal from the exported kernel symbols and replacement with
__find_vma. This function is implemented in the header file and is
still available to drivers, but exported function is changed to
__find_vma. This causes ABI breakage with the following error:

ERROR: Differences between ksymtab and symbol list detected!
Symbols missing from ksymtab:
 - find_vma

Replace find_vma with new __find_vma in the symbol lists.

[1] https://lore.kernel.org/all/20220128131006.67712-13-michel@lespinasse.org/


Bug: 161210518
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I23fdb68b7fd4d907354fc5902dca9ddec8060319