Add P2P dialog PIN length validation

Add validation to P2P dialog PIN length, disabling the positive button
unless the PIN length is 4 or 8.

Bug: 234326049
Test: adb shell cmd wifi launch-dialog-p2p-invitation-received name -p,
verify positive button only appears if the input length is 4 or 8.

Change-Id: I0f8b01305c0b4b54e57dd6fcd8b5d6cbca2433b2
1 file changed