Fix imports in AlertDialog

app/src/main/java/org/thoughtcrime/securesms/ui/AlertDialog.kt

@@ -5,7 +5,6 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
-import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.material.Icon
 import androidx.compose.material.IconButton
 import androidx.compose.material.MaterialTheme
@@ -17,7 +16,6 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.RectangleShape
 import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.style.TextAlign
-import androidx.compose.ui.unit.dp
 import network.loki.messenger.R
 import org.thoughtcrime.securesms.ui.color.LocalColors