aapt: silence these warnings

to show them, set SHOW_MANIFEST_WARNING

Change-Id: I8fd3617e03ca535df1ae0ebdb3dde3a67eb2737b
aapt: i hate if (true) statements

Change-Id: If0d39f4d942067ae2d4ee4d32490b6e079a5f60d
aapt: we dont care about uncommented public symbols

export SHOW_UNCOMMENTED_SYMBOL_WARNING to show them

Change-Id: I6e6461b54e5cd3a9c09efeb8df3172e48bbfa8e5
aapt: introduce SHOW_EXTENDED_WARNINGS

a quick switch for enabling various warnings we silenced

export SHOW_EXTENDED_WARNINGS to show all silenced warnings

Change-Id: I298f36469d78e335a461f5ccfc2a66aa2976ceac
aapt: suppress string resources build warnings

warnings suppressed are:
aapt: warning: **** string '%s' has no default or required localization for
aapt: warning: string '%s' has no default translation in

Patch Set 2: move ifdef and only suppress warnings for packages that
             define NO_DEFAULT_TRANSLATION_WARNINGS and/or
             NO_LOCALIZATION_WARNING

Patch Set 3: by default do not show warnings unless
             SHOW_DEFAULT_TRANSLATION_WARNINGS and/or
             SHOW_LOCALIZATION_WARNINGS

Change-Id: I50ef2a623959a1cc53053b446328df8e34cc99e8