Cleanup date formats that specify the same field multiple times.

One of the usages was almost always meant to be something else. Most commonly the format reuses "m" (minutes of hour) instead of "M" (month of year) or "s" (second of minute) instead of "S" (milliseconds).

Eg: "mm/dd/yyyy hh:mm:ss.sss" instead of "MM/dd/yyyy hh:mm:ss.SSS"

#busy-beavers

PiperOrigin-RevId: 571995047

lib/javatests/com/google/android/material/datepicker/SingleDateSelectorTest.java

@@ -231,13 +231,13 @@ public void textFieldPlaceholder_usesDefaultFormat() {
 
   @Test
   public void textFieldPlaceholder_usesCustomFormat() {
-    singleDateSelector.setTextInputFormat(new SimpleDateFormat("kk:mm:ss mm/dd/yyyy"));
+    singleDateSelector.setTextInputFormat(new SimpleDateFormat("kk:mm:ss MM/dd/yyyy"));
     View root = getRootView();
     ((ViewGroup) activity.findViewById(android.R.id.content)).addView(root);
 
     TextInputLayout textInputLayout = root.findViewById(R.id.mtrl_picker_text_input_date);
 
-    assertThat(textInputLayout.getPlaceholderText().toString()).isEqualTo("kk:mm:ss mm/dd/yyyy");
+    assertThat(textInputLayout.getPlaceholderText().toString()).isEqualTo("kk:mm:ss MM/dd/yyyy");
   }
 
   @Test