Actually use a waveform instead of the frequency data

res/css/_components.scss

@@ -246,7 +246,7 @@
 @import "./views/toasts/_AnalyticsToast.scss";
 @import "./views/toasts/_NonUrgentEchoFailureToast.scss";
 @import "./views/verification/_VerificationShowSas.scss";
-@import "./views/voice_messages/_FrequencyBars.scss";
+@import "./views/voice_messages/_Waveform.scss";
 @import "./views/voip/_CallContainer.scss";
 @import "./views/voip/_CallView.scss";
 @import "./views/voip/_DialPad.scss";

res/css/views/voice_messages/_Waveform.scss

@@ -14,14 +14,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-.mx_FrequencyBars {
+.mx_Waveform {
     position: relative;
     height: 30px; // tallest bar can only be 30px
 
     display: flex;
     align-items: center; // so the bars grow from the middle
 
-    .mx_FrequencyBars_bar {
+    .mx_Waveform_bar {
         width: 2px;
         margin-left: 1px;
         margin-right: 1px;