align with primary sidebar (microsoft#195501)

Author: sandy081

src/vs/workbench/browser/parts/auxiliarybar/media/auxiliaryBarPart.css

@@ -14,6 +14,10 @@
 	background-color: var(--vscode-sideBar-background);
 }
 
+.monaco-workbench .part.auxiliarybar > .title > .composite-bar-container {
+	flex: 1;
+}
+
 .monaco-workbench .part.auxiliarybar > .title > .composite-bar-container > .composite-bar > .monaco-action-bar .action-item:hover .action-label,
 .monaco-workbench .part.auxiliarybar > .title > .composite-bar-container > .composite-bar > .monaco-action-bar .action-item:focus .action-label {
 	color: var(--vscode-sideBarTitle-foreground) !important;