[RenderScript] Update the documentation of Script.LaunchOptions

Bug: 26916665

  - Add description of the endArg.
  - Update the example.
  - Update the incorrect description.

Change-Id: Idd07db5d790e2d6462fff9cb580115ec45cfd4f0
(cherry picked from commit 53fdcfbe63c1d4b2f1cbee6e72a6dd13f41dc1bc)
diff --git a/rs/java/android/renderscript/Script.java b/rs/java/android/renderscript/Script.java
index 84f980d..815d478 100644
--- a/rs/java/android/renderscript/Script.java
+++ b/rs/java/android/renderscript/Script.java
@@ -542,21 +542,22 @@
 
     /**
      * Class for specifying the specifics about how a kernel will be
-     * launched
+     * launched.
      *
      * This class can specify a potential range of cells on which to
      * run a kernel.  If no set is called for a dimension then this
      * class will have no impact on that dimension when the kernel
      * is executed.
      *
-     * The forEach launch will operate over the intersection of the
-     * dimensions.
+     * The forEach kernel launch will operate over the intersection of
+     * the dimensions.
      *
      * Example:
      * LaunchOptions with setX(5, 15)
      * Allocation with dimension X=10, Y=10
-     * The resulting forEach run would execute over x = 5 to 10 and
-     * y = 0 to 10.
+     * The resulting forEach run would execute over:
+     * x = 5 to 9 (inclusive) and
+     * y = 0 to 9 (inclusive).
      *
      *
      */
@@ -570,11 +571,11 @@
         private int strategy;
 
         /**
-         * Set the X range.  If the end value is set to 0 the X dimension is not
-         * clipped.
+         * Set the X range. xstartArg is the lowest coordinate of the range,
+         * and xendArg-1 is the highest coordinate of the range.
          *
          * @param xstartArg Must be >= 0
-         * @param xendArg Must be >= xstartArg
+         * @param xendArg Must be > xstartArg
          *
          * @return LaunchOptions
          */
@@ -588,11 +589,11 @@
         }
 
         /**
-         * Set the Y range.  If the end value is set to 0 the Y dimension is not
-         * clipped.
+         * Set the Y range. ystartArg is the lowest coordinate of the range,
+         * and yendArg-1 is the highest coordinate of the range.
          *
          * @param ystartArg Must be >= 0
-         * @param yendArg Must be >= ystartArg
+         * @param yendArg Must be > ystartArg
          *
          * @return LaunchOptions
          */
@@ -606,11 +607,11 @@
         }
 
         /**
-         * Set the Z range.  If the end value is set to 0 the Z dimension is not
-         * clipped.
+         * Set the Z range. zstartArg is the lowest coordinate of the range,
+         * and zendArg-1 is the highest coordinate of the range.
          *
          * @param zstartArg Must be >= 0
-         * @param zendArg Must be >= zstartArg
+         * @param zendArg Must be > zstartArg
          *
          * @return LaunchOptions
          */