Update the KeyMint feature version to 300

As we've updated the KeyMint version to 3, update the default feature
version to 300. That allows external developers to tell which KeyMint
version is running on the device.

Bug: 244732345
Test: atest android.keystore.cts.DeviceOwnerKeyManagementTest
Change-Id: I9b333eeb77a62a79e8e664d40b5564767643aa3d
diff --git a/security/keymint/aidl/default/android.hardware.hardware_keystore.xml b/security/keymint/aidl/default/android.hardware.hardware_keystore.xml
index 2ebf1fe..4c75596 100644
--- a/security/keymint/aidl/default/android.hardware.hardware_keystore.xml
+++ b/security/keymint/aidl/default/android.hardware.hardware_keystore.xml
@@ -14,5 +14,5 @@
      limitations under the License.
 -->
 <permissions>
-  <feature name="android.hardware.hardware_keystore" version="200" />
+  <feature name="android.hardware.hardware_keystore" version="300" />
 </permissions>