Do not generate SHT_RELR relocations before API 28

This patch fixes an issue that SHR_RELR relocation is not supported by
SDK version earlier than API 28. We only turn it on when SDK is not
used, or SDK version is newer than or equal to API 28.

Test: m -j48 for aosp_taimen-userdebug
Bug: http://b/119086751
Change-Id: I33124ae4f35fb8c00ae9103e8c04e2d4ccd5fec3