Documented adb install --instant

Test: m -j32 adb && ./out/host/linux-x86/bin/adb help 2>&1 | grep instant
Bug: 79422318

Change-Id: I2830a9e3cf81becac1a6334670d8dc487fe72322
    (cherry picked from commit 807be77c25276cecd8a939dad2cdb3c7ac1db975)
1 file changed