Refactor the android_mallopt code.

Rather than have two copies of some of the android_mallopt code for
the static and dynamic libc, have it all in one file.

Test: bionic-unit-tests and bionic-unit-tests-static 32/64 pass.
Change-Id: I2c307714bdfb88fae3c5a628c5cdf2cd4b1e52d8
diff --git a/libc/Android.bp b/libc/Android.bp
index 08d2606..5ae8c4f 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1490,6 +1490,7 @@
     srcs: [
         "arch-common/bionic/crtbegin_so.c",
         "arch-common/bionic/crtbrand.S",
+        "bionic/android_mallopt.cpp",
         "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/icu.cpp",
@@ -1508,6 +1509,7 @@
 filegroup {
     name: "libc_sources_static",
     srcs: [
+        "bionic/android_mallopt.cpp",
         "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
         "bionic/icu_static.cpp",