Revert "ANDROID: Revert "arm: move ELF_ET_DYN_BASE to 4MB""

This reverts commit 040c05c6.

ASan can handle the new memory layout in Android P and later, which
means this change can be reverted in 4.14.

Bug: 67425063
Signed-off-by: Evgenii Stepanov <eugenis@google.com>
Change-Id: I128de2797bca0bc17fe991e1cb48788ecf5f25de