Fix TTML position parsing (#2493)

The TTML parser would accept 100%, but not 100.0%.

This makes the parser more flexible, so even 100.00000% is valid.

Fixes #2477

CONTRIBUTORS

@@ -25,6 +25,7 @@
 Aaron Vaage <vaage@google.com>
 Alvaro Velad Galvan <alvaro.velad@mirada.tv>
 Andy Hochhaus <ahochhaus@samegoal.com>
+Ashutosh Kumar Mukhiya <ashukm4@gmail.com>
 Benjamin Wallberg <benjamin.wallberg@bonnierbroadcasting.com>
 Boris Cupac <borisrt2309@gmail.com>
 Bryan Huh <bhh1988@gmail.com>

lib/text/ttml_text_parser.js

@@ -1061,7 +1061,7 @@ shaka.text.TtmlTextParser.RateInfo_ = class {
  * @example 50.17% 10%
  */
 shaka.text.TtmlTextParser.percentValues_ =
-    /^(\d{1,2}(?:\.\d+)?|100)% (\d{1,2}(?:\.\d+)?|100)%$/;
+    /^(\d{1,2}(?:\.\d+)?|100(?:\.0+)?)% (\d{1,2}(?:\.\d+)?|100(?:\.0+)?)%$/;
 
 /**
  * @const