Add WifiOemConfigStoreMigrationHook class for OEM migration

Add a helper class (not part of the wifi mainline module) to migrate
config store data from existing OEM devices. This will be used when the
device upgrades from a build containing OEM impl of wifi to a
build containing wifi mainline module. OEM should implement this
class if they had any non-AOSP changes in the config store
format/field names on their devices.

Bug: 142394776
Test: Compiles
Change-Id: Ie11e0ffe8e4b8f1edcaa23d35284c3b564dc97f4
diff --git a/wifi/Android.bp b/wifi/Android.bp
index 180368c..286be0b 100644
--- a/wifi/Android.bp
+++ b/wifi/Android.bp
@@ -32,6 +32,7 @@
         // framework-wifi.jar. This is not a good idea, should move WifiNetworkScoreCache
         // to a separate package.
         "java/android/net/wifi/WifiNetworkScoreCache.java",
+        "java/android/net/wifi/WifiOemConfigStoreMigrationHook.java",
         "java/android/net/wifi/wificond/*.java",
         ":libwificond_ipc_aidl",
     ],