android: Expose setting of the JavaVM.

Needed when we use the liblo-native-code as a library.

Change-Id: Ia4d1d72f2203a96d1196d015b521201919bbb165
Reviewed-on: https://gerrit.libreoffice.org/67965
Tested-by: Jenkins
Reviewed-by: Jan Holesovsky <kendy@collabora.com>

include/osl/detail/android-bootstrap.h

@@ -35,6 +35,10 @@ int lo_apk_closedir(lo_apk_dir *dirp);
 
 int lo_apk_lstat(const char *path, struct stat *statp);
 
+/// "libreofficekit_" prefix, because it is exported from the .so, when we are
+/// initializing the JNI externally.
+void libreofficekit_set_javavm(JavaVM *vm);
+
 JavaVM *lo_get_javavm(void);
 
 const char *lo_get_app_data_dir(void);

sal/android/lo-bootstrap.c

@@ -897,6 +897,13 @@ Java_org_libreoffice_android_Bootstrap_address_1of_1direct_1byte_1buffer(JNIEnv
     return (jlong) (intptr_t) (*env)->GetDirectBufferAddress(env, bbuffer);
 }
 
+__attribute__ ((visibility("default")))
+void
+libreofficekit_set_javavm(JavaVM *vm)
+{
+    the_java_vm = vm;
+}
+
 __attribute__ ((visibility("default")))
 JavaVM *
 lo_get_javavm(void)