wifi: fix setting WAPI psk hex bytes

setPsk only accepts exact 32 bytes, but the
length of WAPI psk hex bytes might vary.

Use existing HAL APIs to route WAPI PSK hex.

Bug: 139257562
Test: atest FrameworksWifiTest
Change-Id: I5f2f22c445c023ba1df362613d683977408e6506
3 files changed