Parse MFPC/MFPR from RSNE correctly

Parse MFPC/MFPR correctly from the RSN capabilities field in the
RSN Element, even if the optional Group Management Cipher Suite
field is not used (0 bytes).

Refer to Figure 9-255—RSNE format, in IEEE 802.11-2016 for more
details.

Bug: 276505820
Test: atest InformationElementUtilTest
Test: Verify MFPR/MFPC in dumpsys wifiscanner appears for
WPA3-Enterprise network using LANCOM LN-830E AP.

Change-Id: Ia41a8af578a77f08fb6a73d5733f7c9f9f89b97b
2 files changed