Imported from GitHub PR https://github.com/abseil/abseil-cpp/pull/1604

Looks like abseil is not using any of the APIs listed in https://developer.apple.com/documentation/bundleresources/privacy_manifest_files/describing_use_of_required_reason_api?language=objc, so adding an empty manifest file.

fixes #1602
Merge 79da4bd7b54949d5e01c04623842ea1d0d4fbe59 into f7d2b13e

Merging this change closes #1604

COPYBARA_INTEGRATE_REVIEW=https://github.com/abseil/abseil-cpp/pull/1604 from HannahShiSFB:privacy-manifests 79da4bd7b54949d5e01c04623842ea1d0d4fbe59
PiperOrigin-RevId: 600525731
Change-Id: I3fbc6dcc6e47032665a9fa72c000ae245a25dd52