Check network info for metering state on AccessPoint.

This resolves bug where networks manually marked as metered by Settings
UI were not tagged with a metered friction icon in the Wi-Fi picker.

Bug: 38460378
Test: runtest --path
frameworks/base/packages/SettingsLib/tests/integ/src/com/android/settingslib/wifi/AccessPointTest.java

Change-Id: I2ffe25e898ac001549e7d7492a2aa335ee415a4e