[Vertex AI] Return ImagenInlineImage.data as binary

Author: andrewheard

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

@@ -16,6 +16,7 @@
 
 package com.google.firebase.vertexai.type
 
+import android.util.Base64
 import com.google.firebase.vertexai.ImagenModel
 import kotlinx.serialization.Serializable
 
@@ -53,7 +54,7 @@ internal constructor(public val images: List<T>, public val filteredReason: Stri
     val raiFilteredReason: String? = null,
   ) {
     internal fun toPublicInline() =
-      ImagenInlineImage(bytesBase64Encoded!!.toByteArray(), mimeType!!)
+      ImagenInlineImage(Base64.decode(bytesBase64Encoded!!, Base64.NO_WRAP), mimeType!!)
 
     internal fun toPublicGCS() = ImagenGCSImage(gcsUri!!, mimeType!!)
   }

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

@@ -18,7 +18,6 @@ package com.google.firebase.vertexai.type
 
 import android.graphics.Bitmap
 import android.graphics.BitmapFactory
-import android.util.Base64
 
 /**
  * Represents an Imagen-generated image that is contained inline
@@ -34,7 +33,6 @@ internal constructor(public val data: ByteArray, public val mimeType: String) {
    * Returns the image as an Android OS native [Bitmap] so that it can be saved or sent to the UI.
    */
   public fun asBitmap(): Bitmap {
-    val data = Base64.decode(data, Base64.NO_WRAP)
     return BitmapFactory.decodeByteArray(data, 0, data.size)
   }
 }