No use to build tools or extras when cross-compiling

Also, for some reason building the endian check thing fails when trying to use
Clang for Android, so just hardcode it.

Change-Id: I04fb7ba4f88a1dc6a4e743b39e7c0cd19d7e3598

external/icu/ExternalProject_icu.mk

@@ -77,8 +77,9 @@ $(call gb_ExternalProject_get_state_target,icu,build) :
 		CXXFLAGS=$(icu_CXXFLAGS) LDFLAGS=$(icu_LDFLAGS) \
 		./configure \
 			--disable-layout --disable-samples \
+			$(if $(CROSS_COMPILING),--disable-tools --disable-extras) \
 			$(if $(filter IOS ANDROID,$(OS)),--disable-dyload) \
-			$(if $(filter ANDROID,$(OS)),--disable-strict) \
+			$(if $(filter ANDROID,$(OS)),--disable-strict ac_cv_c_bigendian=no) \
 			$(if $(filter SOLARIS AIX,$(OS)),--disable-64bit-libs) \
 			$(if $(filter TRUE,$(DISABLE_DYNLOADING)),\
 				--enable-static --disable-shared,\