Fix typo in absl/time/time.h

PiperOrigin-RevId: 443726104
Change-Id: Ibd015472fe3e403c2da49bdeeb365ca9a817b8a5

absl/time/time.h

@@ -579,7 +579,7 @@ bool ParseDuration(absl::string_view dur_string, Duration* d);
 
 
 // AbslParseFlag()
 // AbslParseFlag()
 //
 //
-// Parses a command-line flag string representation `text` into a a Duration
+// Parses a command-line flag string representation `text` into a Duration
 // value. Duration flags must be specified in a format that is valid input for
 // value. Duration flags must be specified in a format that is valid input for
 // `absl::ParseDuration()`.
 // `absl::ParseDuration()`.
 bool AbslParseFlag(absl::string_view text, Duration* dst, std::string* error);
 bool AbslParseFlag(absl::string_view text, Duration* dst, std::string* error);