Fix a typo

s/will/while/ for the --no-window-animation explanation.

Change-Id: Ia068809d385cc4f54f9603a8713a581fd4f59440
diff --git a/cmds/am/src/com/android/commands/am/Am.java b/cmds/am/src/com/android/commands/am/Am.java
index 3bbdc48..87ea4fd 100644
--- a/cmds/am/src/com/android/commands/am/Am.java
+++ b/cmds/am/src/com/android/commands/am/Am.java
@@ -153,7 +153,7 @@
                 "        test runners.\n" +
                 "    --user <USER_ID> | current: Specify user instrumentation runs in;\n" +
                 "        current user if not specified.\n" +
-                "    --no-window-animation: turn off window animations will running.\n" +
+                "    --no-window-animation: turn off window animations while running.\n" +
                 "\n" +
                 "am profile: start and stop profiler on a process.  The given <PROCESS> argument\n" +
                 "  may be either a process name or pid.  Options are:\n" +