Allow vendor-init-actionable for ro.board.platform and sys.boot_from_charger_mode

ro.board.platform and sys.boot_from_charger_mode are already
public-readable, but they should be used as action triggers as well for
some products including Android Go devices.

Bug: 75987246
Test: succeeded building and tested with taimen
Change-Id: I140a8f7ef3fa9823ceced94b00a413800518c240

init/stable_properties.h

@@ -35,10 +35,12 @@ static const std::set<std::string> kExportedActionableProperties = {
     "persist.bluetooth.btsnoopenable",
     "persist.sys.crash_rcu",
     "persist.sys.zram_enabled",
+    "ro.board.platform",
     "ro.bootmode",
     "ro.build.type",
     "ro.debuggable",
     "sys.boot_completed",
+    "sys.boot_from_charger_mode",
     "sys.retaildemo.enabled",
     "sys.shutdown.requested",
     "sys.usb.config",