[KA09] add keepalive offload permission to shell

This change adds PACKET_KEEPALIVE_OFFLOAD to shell, which allows
shell or code with shell permission identity to use privileged
tcp keepalive offload API.

Bug: 114151147
Test: -atest ConnectivityManagerTest#testCreateTcpKeepalive
      -build, flash, boot

Change-Id: Ib6660a5eaa72f83042596481452be4d415383f02
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index d639e5e..21326e8 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -177,6 +177,8 @@
 
     <!-- Permission needed to run network tests in CTS -->
     <uses-permission android:name="android.permission.MANAGE_TEST_NETWORKS" />
+    <!-- Permission needed to test tcp keepalive offload. -->
+    <uses-permission android:name="android.permission.PACKET_KEEPALIVE_OFFLOAD" />
 
     <application android:label="@string/app_label"
                  android:defaultToDeviceProtectedStorage="true"