MAC Anonymization: wificond SIOCSIFHWADDR sepolicy

Add sepolicy rules to grant wificond permission to use SIOCSIFHWADDR
ioctl. This permission is needed to dynamically change MAC address of
the device when connecting to wifi networks.

Bug: 63905794
Test: Verified manually that wificond can dynamically change MAC
address.

Change-Id: If2c6b955b0b792f706d8438e8e2e018c0b4cfc31