Fix Mistral image_url payload format for vision requests

Author: Android-PowerUser

app/src/main/kotlin/com/google/ai/sample/ScreenCaptureApiClients.kt

@@ -50,10 +50,7 @@ data class ServiceMistralTextContent(@SerialName("text") val text: String) : Ser
 
 @Serializable
 @SerialName("image_url")
-data class ServiceMistralImageContent(@SerialName("image_url") val imageUrl: ServiceMistralImageUrl) : ServiceMistralContent()
-
-@Serializable
-data class ServiceMistralImageUrl(val url: String)
+data class ServiceMistralImageContent(@SerialName("image_url") val imageUrl: String) : ServiceMistralContent()
 
 @Serializable
 data class ServiceMistralResponse(
@@ -104,7 +101,7 @@ internal suspend fun callMistralApi(
                     is TextPart -> if (part.text.isNotBlank()) ServiceMistralTextContent(text = part.text) else null
                     is ImagePart -> {
                         if (supportsScreenshot) {
-                            ServiceMistralImageContent(imageUrl = ServiceMistralImageUrl(url = "data:image/jpeg;base64,${com.google.ai.sample.util.ImageUtils.bitmapToBase64(part.image)}"))
+                            ServiceMistralImageContent(imageUrl = "data:image/jpeg;base64,${com.google.ai.sample.util.ImageUtils.bitmapToBase64(part.image)}")
                         } else null
                     }
                     else -> null

app/src/main/kotlin/com/google/ai/sample/feature/multimodal/PhotoReasoningProviderDtos.kt

@@ -66,12 +66,9 @@ internal data class MistralTextContent(val text: String) : MistralContent()
 @Serializable
 @kotlinx.serialization.SerialName("image_url")
 internal data class MistralImageContent(
-    @kotlinx.serialization.SerialName("image_url") val imageUrl: MistralImageUrl
+    @kotlinx.serialization.SerialName("image_url") val imageUrl: String
 ) : MistralContent()
 
-@Serializable
-internal data class MistralImageUrl(val url: String)
-
 @Serializable
 internal data class MistralResponse(
     val choices: List<MistralChoice>

app/src/main/kotlin/com/google/ai/sample/feature/multimodal/PhotoReasoningViewModel.kt

@@ -1097,9 +1097,7 @@ class PhotoReasoningViewModel(
                     for (bitmap in selectedImages)
                         updatedContent.add(
                             MistralImageContent(
-                                imageUrl = MistralImageUrl(
-                                    url = "data:image/jpeg;base64,${PhotoReasoningSerialization.bitmapToBase64(bitmap)}"
-                                )
+                                imageUrl = "data:image/jpeg;base64,${PhotoReasoningSerialization.bitmapToBase64(bitmap)}"
                             )
                         )
                     apiMessages[apiMessages.lastIndex] = lastUserMsg.copy(content = updatedContent)