Merge remote-tracking branch 'trigger/MAGETWO-96034' into 2.3.0-release-bugs

Author: cpartica

app/code/Magento/Customer/etc/db_schema.xml

@@ -506,7 +506,7 @@
         <column xsi:type="int" name="customer_id" padding="11" unsigned="false" nullable="true" identity="false"
                 comment="Customer Id"/>
         <column xsi:type="varchar" name="session_id" nullable="true" length="64" comment="Session ID"/>
-        <column xsi:type="timestamp" name="last_visit_at" on_update="true" nullable="true" default="CURRENT_TIMESTAMP"
+        <column xsi:type="timestamp" name="last_visit_at" on_update="true" nullable="false" default="CURRENT_TIMESTAMP"
                 comment="Last Visit Time"/>
         <constraint xsi:type="primary" referenceId="PRIMARY">
             <column name="visitor_id"/>

app/code/Magento/Integration/etc/db_schema.xml

@@ -136,7 +136,7 @@
                 comment="User type (admin or customer)"/>
         <column xsi:type="smallint" name="failures_count" padding="5" unsigned="true" nullable="true" identity="false"
                 default="0" comment="Number of failed authentication attempts in a row"/>
-        <column xsi:type="timestamp" name="lock_expires_at" on_update="true" nullable="true" default="CURRENT_TIMESTAMP"
+        <column xsi:type="timestamp" name="lock_expires_at" on_update="true" nullable="false" default="CURRENT_TIMESTAMP"
                 comment="Lock expiration time"/>
         <constraint xsi:type="primary" referenceId="PRIMARY">
             <column name="log_id"/>

app/code/Magento/Sales/etc/db_schema.xml

@@ -769,7 +769,7 @@
         <column xsi:type="varchar" name="order_increment_id" nullable="false" length="32" comment="Order Increment Id"/>
         <column xsi:type="int" name="order_id" padding="10" unsigned="true" nullable="false" identity="false"
                 comment="Order Id"/>
-        <column xsi:type="timestamp" name="order_created_at" on_update="true" nullable="true"
+        <column xsi:type="timestamp" name="order_created_at" on_update="true" nullable="false"
                 default="CURRENT_TIMESTAMP" comment="Order Increment Id"/>
         <column xsi:type="varchar" name="customer_name" nullable="false" length="128" comment="Customer Name"/>
         <column xsi:type="decimal" name="total_qty" scale="4" precision="12" unsigned="false" nullable="true"