Updates documentation to match MAC address restrictions.

Non-system apps targeting the latest SDK will only be able to access
network interfaces that have an IPv4 address set, without being able
to access IPv6-only interfaces. This change updates the documentation
to reflect that.

In addition, the documentation now references Build.VERSION_CODES_R as
the affected targetSdkVersion.

Bug: 141455849
Test: atest NetworkInterfaceTest
Change-Id: I9525fa527cc595a323ff3a000a98112bc3833fdd
1 file changed