FP3: prima: Disable EXT_SCAN, WifiScanner support

This is not fully supported and causes compatibility tests to fail. It
seems that in previous Android versions it got disabled through a
different conditional, but got enabled now. Disable it via firmware ini
now.

Issue: FP3-A13#17
Test: run gts -m GtsGmscoreHostTestCases -t com.google.android.gts.wifi.WifiHostTest#testWifiScannerBatchCorrectBandResults
Test: run gts -m GtsGmscoreHostTestCases -t com.google.android.gts.wifi.WifiHostTest#testWifiScannerBatchMultipleClientsDifferentBand
Change-Id: Ic3e14029a9d608371ad24c3c0f708a1299f06a17
(cherry picked from commit 810e4f21b07ac01f04e81dbcaf17149d0c46883b)