Include credential manager on Wear.

DD: go/wear-dd-credential-manager
Bug: 301168341
Tested: enable/disabled flag with adb command and reboot the system, ·getSystemService("credential")· returns non-null/null result correspondingly.
Change-Id: I500830604ac1d0e64f9bc9a8b19498577a25378c

Author: Shuang Hao

data/etc/wearable_core_hardware.xml

@@ -36,6 +36,7 @@
     <feature name="android.hardware.security.model.compatible" />
 
     <!-- basic system services -->
+    <feature name="android.software.credentials" />
     <feature name="android.software.home_screen" />
     <feature name="android.software.secure_lock_screen" />