Add support for HarmBlockThreshold.OFF (#6843)

Per [b/409040155](https://b.corp.google.com/issues/409040155),

This adds support for `HarmBlockThreshold.OFF`, and also adds javadocs
that clearly articulate the difference it holds from `NONE`.

Author: daymxn

firebase-vertexai/CHANGELOG.md

@@ -1,5 +1,7 @@
 # Unreleased
-
+* [feature] Added support for `HarmBlockThreshold.OFF`. See the
+  [model documentation](https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/configure-safety-filters#how_to_configure_content_filters){: .external}
+  for more information.
 
 # 16.3.0
 * [feature] Emits a warning when attempting to use an incompatible model with

firebase-vertexai/api.txt

@@ -384,6 +384,7 @@ package com.google.firebase.vertexai.type {
     field public static final com.google.firebase.vertexai.type.HarmBlockThreshold LOW_AND_ABOVE;
     field public static final com.google.firebase.vertexai.type.HarmBlockThreshold MEDIUM_AND_ABOVE;
     field public static final com.google.firebase.vertexai.type.HarmBlockThreshold NONE;
+    field public static final com.google.firebase.vertexai.type.HarmBlockThreshold OFF;
     field public static final com.google.firebase.vertexai.type.HarmBlockThreshold ONLY_HIGH;
   }
 

firebase-vertexai/gradle.properties

@@ -12,5 +12,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-version=16.3.1
+version=16.4.0
 latestReleasedVersion=16.3.0

firebase-vertexai/src/main/kotlin/com/google/firebase/vertexai/type/HarmBlockThreshold.kt

@@ -25,6 +25,7 @@ public class HarmBlockThreshold private constructor(public val ordinal: Int) {
 
   internal fun toInternal() =
     when (this) {
+      OFF -> Internal.OFF
       NONE -> Internal.BLOCK_NONE
       ONLY_HIGH -> Internal.BLOCK_ONLY_HIGH
       MEDIUM_AND_ABOVE -> Internal.BLOCK_MEDIUM_AND_ABOVE
@@ -39,6 +40,7 @@ public class HarmBlockThreshold private constructor(public val ordinal: Int) {
     BLOCK_MEDIUM_AND_ABOVE,
     BLOCK_ONLY_HIGH,
     BLOCK_NONE,
+    OFF
   }
 
   public companion object {
@@ -53,5 +55,13 @@ public class HarmBlockThreshold private constructor(public val ordinal: Int) {
 
     /** All content is allowed regardless of harm. */
     @JvmField public val NONE: HarmBlockThreshold = HarmBlockThreshold(3)
+
+    /**
+     * All content is allowed regardless of harm.
+     *
+     * The same as [NONE], but metadata when the corresponding [HarmCategory] occurs will **NOT** be
+     * present in the response.
+     */
+    @JvmField public val OFF: HarmBlockThreshold = HarmBlockThreshold(4)
   }
 }