Allow 64 char HEX string PSKs in WifiSettingsUi

A check for valid PSKs in the settings UI didnt capture the 64 character
HEX string case. Added a check for it.

Test: tests/app/src/com/android/settings/wifi/WifiSettingsUiTest.java
Test: manual verification
Bug: 67492639
Change-Id: Ide738c4a67f23b613883b4a69f8264a0ffb8a0bc
2 files changed