floss: Scanner: Revise the strategy of selecting scan parameter

Originally the settings from the scanner who triggers the scan update is
selected. This causes some issues:
1. When the update is triggered by stop_scan, the settings actually
   refer to a stopped scanner, which makes no sense.
2. When a ScanType::Passive scanner is enabled after a ScanType::Active
   one, this results in passive scan and could break some features.

This patch revised the strategy:
1. Prefer the settings from an enabled ScanType::Active scanner
2. If there is no enabled ScanType::Active scanner, select any enabled
   scanner

Bug: 323979740
Tag: #floss
Test: mmm packages/modules/Bluetooth
Test: Manual test on Cherry/Tomato, no functionality breakage.
      (No behavior change because we use the same settings everywhere)
Flag: EXEMPT, Floss-only changes
Change-Id: I508b888c3dba15226cfe629dff1b3b16c92ab0b5