Add the HAL support for getCachedScanResult.

Bug: 269485350
Test: adb shell cmd wifi get-cached-scan-data
Test: adb shell halutil -get_cached_scan_results
Test: hardware/interfaces/wifi/aidl/default/tests/runtests.sh
Change-Id: Ie94fbdd51a21c25c6aefa4afbd40cfcaabbe0f8c
13 files changed