explore: logs volume histogram: anchor graph to zero (#56200)

public/app/features/explore/Explore.tsx

@@ -244,6 +244,7 @@ export class Explore extends React.PureComponent<Props, ExploreState> {
           annotations={queryResponse.annotations}
           splitOpenFn={splitOpen}
           loadingState={queryResponse.state}
+          anchorToZero={false}
         />
       </Collapse>
     );

public/app/features/explore/ExploreGraph.tsx

@@ -53,6 +53,7 @@ interface Props {
   splitOpenFn?: SplitOpen;
   onChangeTime: (timeRange: AbsoluteTimeRange) => void;
   graphStyle: ExploreGraphStyle;
+  anchorToZero: boolean;
 }
 
 export function ExploreGraph({
@@ -68,6 +69,7 @@ export function ExploreGraph({
   splitOpenFn,
   graphStyle,
   tooltipDisplayMode = TooltipDisplayMode.Single,
+  anchorToZero,
 }: Props) {
   const theme = useTheme2();
   const [showAllTimeSeries, setShowAllTimeSeries] = useState(false);
@@ -80,6 +82,7 @@ export function ExploreGraph({
 
   const [fieldConfig, setFieldConfig] = useState<FieldConfigSource>({
     defaults: {
+      min: anchorToZero ? 0 : undefined,
       color: {
         mode: FieldColorModeId.PaletteClassic,
       },

public/app/features/explore/LogsVolumePanel.tsx

@@ -130,6 +130,7 @@ export function LogsVolumePanel(props: Props) {
           splitOpenFn={splitOpen}
           tooltipDisplayMode={TooltipDisplayMode.Multi}
           onHiddenSeriesChanged={onHiddenSeriesChanged}
+          anchorToZero
         />
       );
     } else {