fix(search): Address Github PR comments

Signed-off-by: Carlos Esteban Lopez <lcarlosesteb@vmware.com>

.changeset/mighty-bears-glow.md

@@ -1,6 +1,10 @@
 ---
-'@backstage/plugin-search-react': patch
-'@backstage/plugin-search': patch
+'@backstage/plugin-search-react': minor
+'@backstage/plugin-search': minor
 ---
 
 Add close button & improve search input.
+
+MUI's Paper wrapping the SearchBar in the SearchPage was removed, we recommend users update their apps accordingly.
+
+SearchBarBase's TextField's placeholder was changed into a label, tests relying on the placeholder should be updated to query for the label instead.

plugins/search-react/src/components/SearchBar/SearchBar.tsx

@@ -164,7 +164,6 @@ export const SearchBarBase: ForwardRefExoticComponent<SearchBarBaseProps> =
               endAdornment: clearButton ? endAdornment : defaultEndAdornment,
             }}
             inputProps={{
-              'aria-label': 'Search',
               ...defaultInputProps,
             }}
             fullWidth={fullWidth}

plugins/search/src/components/SearchModal/SearchModal.tsx

@@ -89,11 +89,6 @@ const useStyles = makeStyles(theme => ({
       marginTop: theme.spacing(1),
     },
   },
-  container: {
-    borderRadius: 30,
-    display: 'flex',
-    height: '2.4em',
-  },
   input: {
     flex: 1,
   },