convert flag options and values in the same line

1. Added the logic in the `androidmk` tool, to convert the flag options and their
corresponding values in the same line;
2. The flags for cc-type modules include asflags, cflags, clang_asflags, clang_cflags,
conlyflags, cppflags, ldflags, and tidy_flags;
3. The flags for java-type modules include apptflags, dxflags,
javacflags, and kotlincflags;
4. Two unit tests were added.

Bug: 192401704
Test: m androidmk
Test: TreeHugger
Change-Id: I2973ad49812e891079cd488e993f2d12c4da3797