refactor: remove redundant min sdk checks

Author: sds100

sysbridge/src/main/java/io/github/sds100/keymapper/sysbridge/adb/AdbKey.kt

@@ -45,7 +45,6 @@ import rikka.core.ktx.unsafeLazy
 
 private const val TAG = "AdbKey"
 
-@RequiresApi(Build.VERSION_CODES.M)
 internal class AdbKey(private val adbKeyStore: AdbKeyStore, name: String) {
 
     companion object {

sysbridge/src/main/java/io/github/sds100/keymapper/sysbridge/adb/AdbManager.kt

@@ -76,11 +76,7 @@ class AdbManagerImpl @Inject constructor(@ApplicationContext private val ctx: Co
 
     override suspend fun pair(code: String): KMResult<Unit> {
         return pairMutex.withLock {
-            val port = adbPairMdns.discoverPort()
-
-            if (port == null) {
-                return@withLock AdbError.ServerNotFound
-            }
+            val port = adbPairMdns.discoverPort() ?: return@withLock AdbError.ServerNotFound
 
             return@withLock getAdbKey().then { key ->
                 val pairingClient = AdbPairingClient(LOCALHOST, port, code, key)