external/boringssl: Sync to e34bcc91.

This includes the following changes:

https://boringssl.googlesource.com/boringssl/+log/0e9138d295cd556e830dc8b3be735e808680f4bd..e34bcc91c07c0bf65ecc53a814d51f5246007150

This also removes BORINGSSL_ENABLE_RC4_TLS and android_compat_hacks.c as
they are no longer needed.

Test: Built tree, phone boots. Ran cts-tradefed run cts -m CtsLibcoreTestCases
Change-Id: I86df196e1856c338bbf72c60e2e47dd1b74ae537
diff --git a/sources.bp b/sources.bp
index 49333bb..e42211f 100644
--- a/sources.bp
+++ b/sources.bp
@@ -17,7 +17,6 @@
 cc_defaults {
     name: "libcrypto_sources",
     srcs: [
-        "android_compat_hacks.c",
         "android_compat_keywrap.c",
         "err_data.c",
         "src/crypto/aes/aes.c",
@@ -497,7 +496,7 @@
         "src/crypto/hkdf/hkdf_test.c",
         "src/crypto/hmac/hmac_test.cc",
         "src/crypto/lhash/lhash_test.c",
-        "src/crypto/modes/gcm_test.c",
+        "src/crypto/modes/gcm_test.cc",
         "src/crypto/newhope/newhope_statistical_test.cc",
         "src/crypto/newhope/newhope_test.cc",
         "src/crypto/newhope/newhope_vectors_test.cc",