Export of internal Abseil changes

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ea0cfebeb69b25bec343652bbe1a203f5476c51a by Mark Barolak <mbar@google.com>:

Change "std::string" to "string" in places where a "std::" qualification was incorrectly inserted by automation.

PiperOrigin-RevId: 300108520
GitOrigin-RevId: ea0cfebeb69b25bec343652bbe1a203f5476c51a
Change-Id: Ie3621e63a6ebad67b9fe56a3ebe33e1d50dac602

absl/time/internal/cctz/include/cctz/time_zone.h

@@ -209,7 +209,7 @@ class time_zone {
   // version() and description() provide additional information about the
   // time zone. The content of each of the returned strings is unspecified,
   // however, when the IANA Time Zone Database is the underlying data source
-  // the version() std::string will be in the familar form (e.g, "2018e") or
+  // the version() string will be in the familar form (e.g, "2018e") or
   // empty when unavailable.
   //
   // Note: These functions are for informational or testing purposes only.

absl/time/internal/cctz/include/cctz/zone_info_source.h

@@ -37,7 +37,7 @@ class ZoneInfoSource {
 
   // Until the zoneinfo data supports versioning information, we provide
   // a way for a ZoneInfoSource to indicate it out-of-band.  The default
-  // implementation returns an empty std::string.
+  // implementation returns an empty string.
   virtual std::string Version() const;
 };