android: avoid connect for USB target

The "adb connect" command is not required for USB connected devices.
This patch is a small update to use "adb connect" only for android devices
accessed by IP address.

Signed-off-by: Patrick Bellasi <patrick.bellasi@arm.com>
diff --git a/devlib/utils/android.py b/devlib/utils/android.py
index 0444b67..e6db188 100644
--- a/devlib/utils/android.py
+++ b/devlib/utils/android.py
@@ -265,6 +265,10 @@
 
 def adb_connect(device, timeout=None, attempts=MAX_ATTEMPTS):
     _check_env()
+    # Connect is required only for ADB-over-IP
+    if "." not in device:
+        logger.debug('Device connected via USB, connect not required')
+        return
     tries = 0
     output = None
     while tries <= attempts: