Don't throw in FullScore#policyNameOf.

This code is correct on userdebug builds, but it is dangerous on
user builds because proguard might strip out the POLICY_*
constants and that would lead to crashes.

For now just log a wtf if an invalid policy name is found. A
better solution would be to make MessageUtils robust to this
problem, e.g., by having it store the SparseArray internally and
providing getters that do not throw, instead of the current
behaviour that returns the SparseArray. That is left to a future
CL.

Fix: 227161413
Test: atest FullScoreTest
Change-Id: I68b69ee9dd84773018e62c9a8f43e754ae04c486

tests/unit/java/com/android/server/connectivity/FullScoreTest.kt

@@ -22,6 +22,7 @@ import android.net.NetworkScore.KEEP_CONNECTED_NONE
 import android.os.Build
 import android.text.TextUtils
 import android.util.ArraySet
+import android.util.Log
 import androidx.test.filters.SmallTest
 import com.android.server.connectivity.FullScore.MAX_CS_MANAGED_POLICY
 import com.android.server.connectivity.FullScore.POLICY_ACCEPT_UNVALIDATED
@@ -32,11 +33,12 @@ import com.android.server.connectivity.FullScore.POLICY_IS_VALIDATED
 import com.android.server.connectivity.FullScore.POLICY_IS_VPN
 import com.android.testutils.DevSdkIgnoreRule
 import com.android.testutils.DevSdkIgnoreRunner
+import org.junit.After
+import org.junit.Before
 import org.junit.Test
 import org.junit.runner.RunWith
 import kotlin.reflect.full.staticProperties
 import kotlin.test.assertEquals
-import kotlin.test.assertFailsWith
 import kotlin.test.assertFalse
 import kotlin.test.assertTrue
 
@@ -63,6 +65,23 @@ class FullScoreTest {
         return mixInScore(nc, nac, validated, false /* yieldToBadWifi */, destroyed)
     }
 
+    private val TAG = this::class.simpleName
+
+    private var wtfHandler: Log.TerribleFailureHandler? = null
+
+    @Before
+    fun setUp() {
+        // policyNameOf will call Log.wtf if passed an invalid policy.
+        wtfHandler = Log.setWtfHandler() { tagString, what, system ->
+            Log.d(TAG, "WTF captured, ignoring: $tagString $what")
+        }
+    }
+
+    @After
+    fun tearDown() {
+        Log.setWtfHandler(wtfHandler)
+    }
+
     @Test
     fun testGetLegacyInt() {
         val ns = FullScore(50, 0L /* policy */, KEEP_CONNECTED_NONE)
@@ -101,10 +120,9 @@ class FullScoreTest {
             assertFalse(foundNames.contains(name))
             foundNames.add(name)
         }
-        assertFailsWith<IllegalArgumentException> {
-            FullScore.policyNameOf(MAX_CS_MANAGED_POLICY + 1)
-        }
         assertEquals("IS_UNMETERED", FullScore.policyNameOf(POLICY_IS_UNMETERED))
+        val invalidPolicy = MAX_CS_MANAGED_POLICY + 1
+        assertEquals(Integer.toString(invalidPolicy), FullScore.policyNameOf(invalidPolicy))
     }
 
     fun getAllPolicies() = Regex("POLICY_.*").let { nameRegex ->