Don't do the developer options countdown for secondary users.

Bug: 7469031
Change-Id: I794cb8b67a9221cc4fcd2dd6208777648c818fe0
Settings: remove taps to become a developer

Developer settings are enabled by default, so having this "feature"
in the Settings app is pointless and annoying. Remove it to improve
the UX.

PS2: Remove some strings too

Change-Id: I87fc6aadb8969717ea55df345ffab6f8ee397882
Signed-off-by: Rohan Mathur <rohanmathur34@gmail.com>