Fix DvbParser bug

Issue: #2957

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=160628086

library/core/src/main/java/com/google/android/exoplayer2/text/dvb/DvbParser.java

@@ -667,13 +667,15 @@ import java.util.List;
       int runLength = 0;
       int clutIndex = 0;
       int peek = data.readBits(2);
-      if (!data.readBit()) {
+      if (peek != 0x00) {
         runLength = 1;
         clutIndex = peek;
       } else if (data.readBit()) {
         runLength = 3 + data.readBits(3);
         clutIndex = data.readBits(2);
-      } else if (!data.readBit()) {
+      } else if (data.readBit()) {
+        runLength = 1;
+      } else {
         switch (data.readBits(2)) {
           case 0x00:
             endOfPixelCodeString = true;