fixed setting keyboard accessibility issue (#1081)

src/Common/Tooltip/InfoTooltip.tsx

@@ -9,7 +9,7 @@ export const InfoTooltip: React.FunctionComponent<TooltipProps> = ({ children }:
   return (
     <span>
       <TooltipHost content={children}>
-        <Icon iconName="Info" ariaLabel="Info" className="panelInfoIcon" />
+        <Icon iconName="Info" ariaLabel="Info" className="panelInfoIcon" tabIndex={0} />
       </TooltipHost>
     </span>
   );

src/Explorer/Controls/ThroughputInput/__snapshots__/ThroughputInput.test.tsx.snap

@@ -345,12 +345,14 @@ exports[`ThroughputInput Pane should render Default properly 1`] = `
                     ariaLabel="Info"
                     className="panelInfoIcon"
                     iconName="Info"
+                    tabIndex={0}
                   >
                     <IconBase
                       ariaLabel="Info"
                       className="panelInfoIcon"
                       iconName="Info"
                       styles={[Function]}
+                      tabIndex={0}
                       theme={
                         Object {
                           "disableGlobalClassNames": false,
@@ -630,6 +632,7 @@ exports[`ThroughputInput Pane should render Default properly 1`] = `
                         className="panelInfoIcon root-57"
                         data-icon-name="Info"
                         role="img"
+                        tabIndex={0}
                       >
                         
                       </i>
@@ -1327,12 +1330,14 @@ exports[`ThroughputInput Pane should render Default properly 1`] = `
                         ariaLabel="Info"
                         className="panelInfoIcon"
                         iconName="Info"
+                        tabIndex={0}
                       >
                         <IconBase
                           ariaLabel="Info"
                           className="panelInfoIcon"
                           iconName="Info"
                           styles={[Function]}
+                          tabIndex={0}
                           theme={
                             Object {
                               "disableGlobalClassNames": false,
@@ -1612,6 +1617,7 @@ exports[`ThroughputInput Pane should render Default properly 1`] = `
                             className="panelInfoIcon root-57"
                             data-icon-name="Info"
                             role="img"
+                            tabIndex={0}
                           >
                             
                           </i>

src/Explorer/Panes/SettingsPane/SettingsPane.tsx

@@ -195,7 +195,6 @@ export const SettingsPane: FunctionComponent = () => {
                 step={1}
                 className="textfontclr"
                 role="textbox"
-                tabIndex={0}
                 id="max-degree"
                 value={"" + maxDegreeOfParallelism}
                 onIncrement={(newValue) => setMaxDegreeOfParallelism(parseInt(newValue) + 1 || maxDegreeOfParallelism)}

src/Explorer/Panes/SettingsPane/__snapshots__/SettingsPane.test.tsx.snap

@@ -123,7 +123,6 @@ exports[`Settings Pane should render Default properly 1`] = `
           onValidate={[Function]}
           role="textbox"
           step={1}
-          tabIndex={0}
           value="6"
         />
       </div>