feat(examples): Increase BigData grid initial row count to 20k (#9163)

Author: tobiu

examples/grid/bigData/ControlsContainer.mjs

@@ -70,7 +70,7 @@ class ControlsContainer extends Container {
                     labelWidth: 120,
                     listeners : {change: 'up.onAmountRowsChange'},
                     store     : ['1000', '5000', '10000', '20000', '50000', '100000'],
-                    value     : '1000',
+                    value     : '20000',
                     width     : 200
                 }, {
                     labelText : 'Amount Columns',

examples/grid/bigData/MainStore.mjs

@@ -18,10 +18,10 @@ class MainStore extends Store {
          */
         amountColumns_: 50,
         /**
-         * @member {Number} amountRows_=1000
+         * @member {Number} amountRows_=20000
          * @reactive
          */
-        amountRows_: 1000,
+        amountRows_: 20000,
         /**
          * @member {Boolean} autoInitRecords=false
          */