Remove unused method TetheringConfiguration#isRandomPrefixBaseEnabled()

This CL removes TetheringConfiguration#isRandomPrefixBaseEnabled(). This
method was used for configuring PrivateAddressCoordinator. Now
PrivateAddressCoordinator doesn't depend on TetheringConfiguration so
we'll remove this unused method.

Bug: 369282577
Change-Id: I2e556cf5dd6c28cd6aba29ee9093a9873a4f4d3f
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
index c9817c9..b3e9c1b 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringConfiguration.java
@@ -182,7 +182,6 @@
     private final int mP2pLeasesSubnetPrefixLength;
 
     private final boolean mEnableWearTethering;
-    private final boolean mRandomPrefixBase;
 
     private final int mUsbTetheringFunction;
     protected final ContentResolver mContentResolver;
@@ -300,8 +299,6 @@
 
         mEnableWearTethering = shouldEnableWearTethering(ctx);
 
-        mRandomPrefixBase = mDeps.isFeatureEnabled(ctx, TETHER_FORCE_RANDOM_PREFIX_BASE_SELECTION);
-
         configLog.log(toString());
     }
 
@@ -390,10 +387,6 @@
         return mEnableWearTethering;
     }
 
-    public boolean isRandomPrefixBaseEnabled() {
-        return mRandomPrefixBase;
-    }
-
     /**
      * Check whether sync SM is enabled then set it to USE_SYNC_SM. This should be called once
      * when tethering is created. Otherwise if the flag is pushed while tethering is enabled,
@@ -455,9 +448,6 @@
         pw.print("mUsbTetheringFunction: ");
         pw.println(isUsingNcm() ? "NCM" : "RNDIS");
 
-        pw.print("mRandomPrefixBase: ");
-        pw.println(mRandomPrefixBase);
-
         pw.print("USE_SYNC_SM: ");
         pw.println(USE_SYNC_SM);
     }