Fix: Reconstruct args as HashMap for FunctionCallPartDto mapping

Addresses a persistent and perplexing compilation type mismatch error in PhotoReasoningMappers.kt when mapping FunctionCallPartDto to the SDK's FunctionCallPart. Despite types appearing identical (Map<String, String?>?), the compiler continued to report a mismatch for the 'args' field.

This commit modifies the `PartDto.toSdk()` function for the `FunctionCallPartDto` case. Instead of previous reconstruction methods, `this.args` (if not null) is now used to populate a new, explicitly created `HashMap<String, String?>`. This `HashMap` instance is then passed to the SDK's `FunctionCallPart` constructor.

This change aims to provide a very concrete and standard `Map` implementation to the SDK, potentially resolving any subtle type incompatibilities or compiler inference issues that previous casting or `toMap()` reconstructions did not.

Author: google-labs-jules[bot]

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

@@ -56,14 +56,13 @@ fun PartDto.toSdk(): Part { // No context needed here as path is absolute
         }
         is BlobPartDto -> BlobPart(mimeType = this.mimeType, blob = this.data)
         is FunctionCallPartDto -> {
-            val sdkArgs: Map<String, String?>? = this.args?.let { dtoArgs ->
-                // Explicitly create a new map to ensure the compiler understands the type correctly.
-                val newMap = mutableMapOf<String, String?>()
-                dtoArgs.entries.forEach { entry -> // Iterate through entries
+            val sdkArgs: HashMap<String, String?>? = this.args?.let { dtoArgs ->
+                // Explicitly create a HashMap.
+                val newMap = hashMapOf<String, String?>()
+                dtoArgs.entries.forEach { entry ->
                     newMap[entry.key] = entry.value
                 }
-                newMap.toMap() // Convert to immutable Map if constructor expects Map, or just newMap if MutableMap is fine.
-                               // Assuming FunctionCallPart constructor takes Map<String, String?>?
+                newMap
             }
             FunctionCallPart(name = this.name, args = sdkArgs)
         }