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

Part of the above change was reverted in 2406280;
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

Author: eugenis

arch/arm64/include/asm/elf.h

@@ -169,7 +169,7 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 #ifdef CONFIG_COMPAT
 
 /* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
-#define COMPAT_ELF_ET_DYN_BASE		0x000400000UL
+#define COMPAT_ELF_ET_DYN_BASE		(2 * TASK_SIZE_32 / 3)
 
 /* AArch32 registers. */
 #define COMPAT_ELF_NGREG		18