ANDROID: cuttlefish_defconfig: Disable DEVTMPFS

This option was enabled for other experiments, and Android doesn't need
or use devtmpfs. However, even just having this feature enabled will
cause selinux denials. Fix the denials by disabling this feature.

Bug: 130468851
Change-Id: I3bf35b2e74f8701d792b85dbdc3f2143d171a8c1
Signed-off-by: Alistair Strachan <astrachan@google.com>