gomobile: pidfd results in a crash on Android 12 or below

[ignoramous]

seccomp on pidfd + sigsys handling on older Android < 12 results in crash.

From:

• Use of pidfd on old Android crashes tailscale/tailscale#13452

2024-11-21 11:15:03.968 DEBUG signal 31 (SIGSYS), code 1 (SYS_SECCOMP), fault addr --------

Upstream:

• x/mobile: seccomp prevented call to disallowed arm64 system call 434 golang/go#70508
• x/mobile/cmd/gomobile: bind, SIGSYS crash on older Android versions golang/go#70495

Cause:

• os: os.checkPidfd() crashes with SIGSYS golang/go#69065