Tweak line-feed regex to avoid exponential backtracking

Before this change, the `(.|\f)*` pattern can lead to exponential
backtracking because it has to try many different combinations. Using
the extra `+` makes the matching 'possessive', so once a match is
found no other alternatives are considered. This is safe for these
regexes, because the pattern in question is always at the end of the
match, so there's no trailing characters that might need to be
'removed' from the match during a backtrack.

This is a follow-up to 2bd2600 and 92677e9.

#cherrypick

PiperOrigin-RevId: 829457102

Author: icbaker

libraries/exoplayer_rtsp/src/main/java/androidx/media3/exoplayer/rtsp/SessionDescriptionParser.java

@@ -36,15 +36,15 @@
 
   // SDP line always starts with an one letter tag, followed by an equal sign. The information
   // under the given tag follows an optional space.
-  private static final Pattern SDP_LINE_PATTERN = Pattern.compile("([a-z])=\\s?((?:.|\f)+)");
+  private static final Pattern SDP_LINE_PATTERN = Pattern.compile("([a-z])=\\s?((?:.|\f)++)");
   // SDP line with a one letter tag, an equal sign, and an empty value.
   private static final Pattern SDP_LINE_WITH_EMPTY_VALUE_PATTERN = Pattern.compile("^([a-z])=$");
   // Matches an attribute line (with a= sdp tag removed. Example: range:npt=0-50.0).
   // Attribute can also be a flag, i.e. without a value, like recvonly. Reference RFC4566 Section 9
   // Page 43, under "token-char".
   private static final Pattern ATTRIBUTE_PATTERN =
       Pattern.compile(
-          "([\\x21\\x23-\\x27\\x2a\\x2b\\x2d\\x2e\\x30-\\x39\\x41-\\x5a\\x5e-\\x7e]+)(?::((?:.|\f)*))?");
+          "([\\x21\\x23-\\x27\\x2a\\x2b\\x2d\\x2e\\x30-\\x39\\x41-\\x5a\\x5e-\\x7e]+)(?::((?:.|\f)*+))?");
   // SDP media description line: <mediaType> <port> <transmissionProtocol> <rtpPayloadType>
   // For instance: audio 0 RTP/AVP 97
   private static final Pattern MEDIA_DESCRIPTION_PATTERN =

libraries/extractor/src/main/java/androidx/media3/extractor/text/webvtt/WebvttCueParser.java

@@ -121,7 +121,7 @@ public final class WebvttCueParser {
   private static final int TEXT_ALIGNMENT_RIGHT = 5;
 
   public static final Pattern CUE_HEADER_PATTERN =
-      Pattern.compile("^(\\S+)\\s+-->\\s+(\\S+)((?:.|\\f)*)?$");
+      Pattern.compile("^(\\S+)\\s+-->\\s+(\\S+)((?:.|\\f)*+)?$");
   private static final Pattern CUE_SETTING_PATTERN = Pattern.compile("(\\S+?):(\\S+)");
 
   private static final char CHAR_LESS_THAN = '<';