ANDROID: Revert "arm64: move ELF_ET_DYN_BASE to 4GB / 4MB"

Part of the above change was reverted in 240628085effc47e86f51fc3fb37bc0e628f9a85;
this change reverts the rest.

This ARM mmap change breaks AddressSanitizer:

Shadow memory range interleaves with an existing memory mapping. ASan cannot proceed correctly. ABORTING.

Revert it until ASAN runtime library is updated to handle it.

Bug: 67425063

Signed-off-by: Evgenii Stepanov <eugenis@google.com>