softap: Use set/getPassphrase to replace set/getWpa2Passphrase

Bug: 142752869
Test: Manual, on/off/setting change for hotspot function
Test: make RunSettingsRoboTests ROBOTEST_FILTER=CodeInspectionTest
Change-Id: I22c89f15a6ef1c5366394431cc5aa7031a573d45
6 files changed