Fix Conscrypt NPE workaround (#7219) (#7230)

(cherry picked from commit 6ba23dc)

Co-authored-by: Phil Glass <phil@phil.glass>

okhttp/src/main/kotlin/okhttp3/internal/platform/android/AndroidSocketAdapter.kt

@@ -17,7 +17,6 @@ package okhttp3.internal.platform.android
 
 import java.lang.reflect.InvocationTargetException
 import java.lang.reflect.Method
-import java.nio.charset.StandardCharsets
 import javax.net.ssl.SSLSocket
 import okhttp3.Protocol
 import okhttp3.internal.platform.AndroidPlatform
@@ -79,17 +78,16 @@ open class AndroidSocketAdapter(private val sslSocketClass: Class<in SSLSocket>)
 
     return try {
       val alpnResult = getAlpnSelectedProtocol.invoke(sslSocket) as ByteArray?
-      if (alpnResult != null) String(alpnResult, StandardCharsets.UTF_8) else null
-    } catch (e: NullPointerException) {
-      when {
-        // https://github.com/square/okhttp/issues/5587
-        e.message == "ssl == null" -> null
-        else -> throw e
-      }
+      alpnResult?.toString(Charsets.UTF_8)
     } catch (e: IllegalAccessException) {
       throw AssertionError(e)
     } catch (e: InvocationTargetException) {
-      throw AssertionError(e)
+      // https://github.com/square/okhttp/issues/5587
+      val cause = e.cause
+      when {
+        cause is NullPointerException && cause.message == "ssl == null" -> null
+        else -> throw AssertionError(e)
+      }
     }
   }