android-configure.sh: Fix --cc=<compiler> option.

+ Fix LOCAL_GENERATED_SOURCES handling
+ Fix missing library dependencies for executables
+ Move generated library files to objs/libs/ (instead of objs/)

Change-Id: If3ebaa7ae856efa9bd3ff9e2c199389989db7f71
diff --git a/android-configure.sh b/android-configure.sh
index a36ece7..02e4d99 100755
--- a/android-configure.sh
+++ b/android-configure.sh
@@ -110,6 +110,12 @@
     fi
 fi
 
+echo "OPTION_CC='$OPTION_CC'"
+if [ -n "$OPTION_CC" ]; then
+    echo "Using specified C compiler: $OPTION_CC"
+    CC="$OPTION_CC"
+fi
+
 # we only support generating 32-bit binaris on 64-bit systems.
 # And we may need to add a -Wa,--32 to CFLAGS to let the assembler
 # generate 32-bit binaries on Linux x86_64.