Set span boundary at word boundary in perf test

The style span interval should be the same with word boundary. This
generates weird test case.

Bug: 72998298
Test: N/A
Change-Id: Id1132a455c8b1dd74e21eaeb259703a33ac3b01f
diff --git a/apct-tests/perftests/core/src/android/text/TextPerfUtils.java b/apct-tests/perftests/core/src/android/text/TextPerfUtils.java
index dccb34b..fefda64 100644
--- a/apct-tests/perftests/core/src/android/text/TextPerfUtils.java
+++ b/apct-tests/perftests/core/src/android/text/TextPerfUtils.java
@@ -76,7 +76,7 @@
         }
 
         SpannableStringBuilder ssb = new SpannableStringBuilder(cs);
-        for (int i = 0; i < ssb.length(); i += wordLen) {
+        for (int i = 0; i < ssb.length(); i += wordLen + 1) {
             final int spanStart = i;
             final int spanEnd = (i + wordLen) > ssb.length() ? ssb.length() : i + wordLen;