Default to not add account post PO provisioning

Most functionalities in TestDPC does not require an account,
so make this the default to save us one tap.

Bug: 154726355
Test: manual
Change-Id: Ic3e2ab4a40024a65dd897eda5379ce356168255c

Author: Rubin Xu

app/src/main/res/layout/activity_add_account.xml

@@ -46,7 +46,6 @@
                 android:id="@+id/add_account"
                 android:layout_width="wrap_content"
                 android:layout_height="@dimen/add_account_option_height"
-                android:checked="true"
                 android:text="@string/add_account" />
 
             <RadioButton
@@ -59,6 +58,7 @@
                 android:id="@+id/add_account_skip"
                 android:layout_width="match_parent"
                 android:layout_height="@dimen/add_account_option_height"
+                android:checked="true"
                 android:text="@string/add_account_skip" />
         </RadioGroup>
     </LinearLayout>