Fix DatagramChannelMulticastTest.test_joinSourceSpecific_groupBind_ipv4

The test was passing the wrong NetworkInterface (IPv6 instead of IPv4)
to a helper method; this would fail if that network interface didn't
also support IPv4.

Bug: 64825787
Test: DatagramChannelMulticastTest

(cherry picked from commit 4aa761e4)

Change-Id: Ic934a03adc8e43dfdb3b50ba215933cf992fb58b
Merged-In: Ic934a03adc8e43dfdb3b50ba215933cf992fb58b