fix: correct typo (#634)

Author: jpoehnelt

calendar/quickstart/src/main/java/CalendarQuickstart.java

@@ -38,7 +38,7 @@
 import java.util.Collections;
 import java.util.List;
 
-/* class to demonstarte use of Calendar events list API */
+/* class to demonstrate use of Calendar events list API */
 public class CalendarQuickstart {
   /**
    * Application name.

docs/quickstart/src/main/java/DocsQuickstart.java

@@ -36,7 +36,7 @@
 import java.util.Collections;
 import java.util.List;
 
-/* class to demonstarte use of Docs get documents API */
+/* class to demonstrate use of Docs get documents API */
 public class DocsQuickstart {
   /**
    * Application name.

drive/activity/quickstart/src/main/java/DriveActivityQuickstart.java

@@ -34,7 +34,7 @@
 import java.util.Arrays;
 import java.util.List;
 
-/* class to demonstarte use of Drive Activity list  API */
+/* class to demonstrate use of Drive Activity list  API */
 public class DriveActivityQuickstart {
   /**
    * Application name.

drive/quickstart/src/main/java/DriveQuickstart.java

@@ -36,7 +36,7 @@
 import java.util.Collections;
 import java.util.List;
 
-/* class to demonstarte use of Drive files list API */
+/* class to demonstrate use of Drive files list API */
 public class DriveQuickstart {
   /**
    * Application name.