Prevent sending sticker attachments with a blank contentType.

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt

@@ -1887,6 +1887,8 @@ class ConversationFragment :
       stickerRecord.size,
       stickerLocator,
       stickerRecord.contentType
+        .takeIf { it.isNotBlank() }
+        ?: MediaUtil.IMAGE_WEBP
     )
 
     sendMessageWithoutComposeInput(slide = slide, clearCompose = clearCompose)

app/src/main/java/org/thoughtcrime/securesms/database/model/StickerRecord.kt

@@ -4,7 +4,7 @@ import android.net.Uri
 import org.thoughtcrime.securesms.mms.PartAuthority
 
 /**
- * Represents a record for a sticker pack in the [StickerTable].
+ * Represents a record for a sticker pack in the [org.thoughtcrime.securesms.database.StickerTable].
  */
 data class StickerRecord(
   @JvmField val rowId: Long,