Add @hide to the biometric interfaces

This change allows the framework to depend on biometric AIDL types, for
example: `android.hardware.biometrics.fingerprint.PointerContext`.

The dependency can be introduced with a `-java-source` target, for
example: `:android.hardware.biometrics.common-V3-java-source`.

The "@hide" annotation informs Metalava that these types are not a
public API (not part of the SDK).

Bug: 218388821
Test: m android.hardware.biometrics.common-update-api
Test: m android.hardware.biometrics.face-update-api
Test: m android.hardware.biometrics.fingerprint-update-api
Change-Id: Ib3327594c64dbb800b9d1744869ceb490d63e553
diff --git a/biometrics/fingerprint/aidl/default/fingerprint-example.xml b/biometrics/fingerprint/aidl/default/fingerprint-example.xml
index 05d1279..e977b98 100644
--- a/biometrics/fingerprint/aidl/default/fingerprint-example.xml
+++ b/biometrics/fingerprint/aidl/default/fingerprint-example.xml
@@ -1,7 +1,7 @@
 <manifest version="1.0" type="device">
     <hal format="aidl">
         <name>android.hardware.biometrics.fingerprint</name>
-        <version>2</version>
+        <version>3</version>
         <fqname>IFingerprint/virtual</fqname>
     </hal>
 </manifest>