base: dlopen/dlsym for liblog when SDK_VER <= 29

libbase doesn't have to rely on dlopen/dlsym to use liblog's new symbols
when it is built for __ANDROID_SDK_VERSION__ > 29.

Bug: 150860940
Test: TARGET_BUILD_APPS="com.android.adbd com.android.resolv" m
      objdump -T ...shared_com.android.resolv/libbase.so | grep LIBLOG_R
        => should be none because resolv apex is targeting 29
      objdump -T ...shared_com.android.adbd/libbase.so | grep LIBLOG_R
        => should list all new symbols because adbd apex is targeting R
      objdump -T ...shared/libbase.so | grep LIBLOG_R
        => should list all new symbols

Merged-In: I7f7f16510d7637cd380fe35ea9ff3e804f38851d
Change-Id: I7f7f16510d7637cd380fe35ea9ff3e804f38851d
(cherry picked from commit 22207e6590)

base/Android.bp

@@ -74,10 +74,6 @@ cc_defaults {
         "test_utils.cpp",
     ],
 
-    static: {
-        cflags: ["-DNO_LIBLOG_DLSYM"],
-    },
-
     cppflags: ["-Wexit-time-destructors"],
     shared_libs: ["liblog"],
     target: {

base/liblog_symbols.cpp

@@ -16,11 +16,9 @@
 
 #include "liblog_symbols.h"
 
-#if defined(__ANDROID__)
-#if !defined(NO_LIBLOG_DLSYM) || defined(__ANDROID_APEX__)
+#if defined(__ANDROID_SDK_VERSION__) && (__ANDROID_SDK_VERSION__ <= 29)
 #define USE_DLSYM
 #endif
-#endif
 
 #ifdef USE_DLSYM
 #include <dlfcn.h>