[Bug] fix missing discover context icon (opensearch-project#1545)

add back icon directive, which injects SVG

Signed-off-by: Josh Romero <[email protected]>

src/plugins/discover/public/get_inner_angular.ts

@@ -147,6 +147,7 @@ export function initializeInnerAngularModule(
     ])
     .config(watchMultiDecorator)
     .run(registerListenEventListener)
+    .directive('icon', (reactDirective) => reactDirective(EuiIcon))
     .directive('renderComplete', createRenderCompleteDirective)
     .directive('discoverLegacy', createDiscoverLegacyDirective)
     .directive('contextErrorMessage', createContextErrorMessageDirective);