Add static_executable property for the binary snapshots

Static binaries have "static_executable: true". This is required to
check if a static lib dependency on 'libc' is allowed for the
snapshot binaries.

Bug: 190690041
Test: 'm nothing' with snapshots
Change-Id: I6c0c7e71fe50624ac233bc43665f4127c0f6103b
1 file changed