Add bulk version of updateLastConversationMessage()

In situations where we want to update multiple conversations (e.g.
during import), we can make it faster by only calling
contentResolver.delete() once.

(We still make separate calls to getConversations() because it doesn't
support multiple IDs, and likewise insertOrUpdateConversation()
doesn't support bulk insert.)

app/src/main/kotlin/org/fossify/messages/extensions/Context.kt

@@ -1114,7 +1114,11 @@ fun Context.deleteSmsDraft(threadId: Long) {
 }
 
 fun Context.updateLastConversationMessage(threadId: Long) {
-    // update the date and the snippet of the thread, by triggering the
+    updateLastConversationMessage(setOf(threadId))
+}
+
+fun Context.updateLastConversationMessage(threadIds: Iterable<Long>) {
+    // update the date and the snippet of the threads, by triggering the
     // following Android code (which runs even if no messages are deleted):
     // https://android.googlesource.com/platform/packages/providers/TelephonyProvider/+/android14-release/src/com/android/providers/telephony/MmsSmsProvider.java#1409
     val uri = Threads.CONTENT_URI
@@ -1122,8 +1126,10 @@ fun Context.updateLastConversationMessage(threadId: Long) {
         "1 = 0" // always-false condition, because we don't actually want to delete any messages
     try {
         contentResolver.delete(uri, selection, null)
-        val newConversation = getConversations(threadId)[0]
-        insertOrUpdateConversation(newConversation)
+        for (threadId in threadIds) {
+            val newConversation = getConversations(threadId)[0]
+            insertOrUpdateConversation(newConversation)
+        }
     } catch (e: Exception) {
     }
 }